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U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY— BULLETIN  No.  66. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


CONTENTS  AND  INDEX. 


Issued  March  17,  1910 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1910. 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BOREAD  OF  ENTOMOLOGY— BULLETIN  No.  66. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau, 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


I.  THE  ASPARAGUS  MINER. 

NOTES  ON  THE  ASPARAGUS  BEETLES. 

By  F.  H.  CHITTENDEN,  Entomologist  in  Charge  of  Breeding  Experiments . 

II.  THE  WATER-CRESS  SOWBUG. 

THE  WATER-CRESS  LEAF-BEETLE. 

By  F.  H.  CHITTENDEN,  Entomologist  in  Charge  of  Breeding  Experiments. 

III.  THE  CRANBERRY  SPANWORM. 

THE  STRIPED  GARDEN  CATERPILLAR. 

By  F.  H.  CHITTENDEN,  Entomologist  in  Charge  of  Breeding  Experiments. 

IV.  THE  LEAFHOPPERS  OF  THE  SUGAR  BEET  AND  THEIR  RELATION  TO  THE 
“CURLY-LEAF”  CONDITION. 

By  E.  D.  BALL,  Ph.  D.,  Special  Field  Agent. 

V.  THE  SEMITROPICAL  ARMY  WORM. 

By  F.  H.  CHITTENDEN  and  H.  M.  RUSSELL. 

VI.  THE  HOP  FLEA-BEETLE. 

By  F.  H.  CHITTENDEN,  Sc.  D.,  in  Charge  of  Truck  Crop  and  Special  Insect  Investigations. 

VII.  MISCELLANEOUS  NOTES  ON  TRUCK-CROP  INSECTS. 

By  F.  H.  CHITTENDEN,  Sc.  D.,  in  Charge  of  Truck  Crop  and  Stored  Product  Insect  Investigations 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1910. 


BUREAU  OF  ENTOMOLOGY. 


L.  O.  Howard,  Entomologist  and  Chief  of  Bureau. 

C.  L.  Marlatt,  Assistant  Entomologist  and  Acting  Chief  in  Absence  of  Chief. 

R.  S.  Clifton,  Executive  Assistant. 

Chas.  J.  Gilliss,  Chief  Clerk. 

F.  H.  Chittenden,  in  charge  of  truck  crop  and  stored  product  insect  investigations. 

A.  D.  Hopkins,  in  charge  of forest  insect  investigations. 

W.  D.  Hunter,  in  charge  of  southern  field  crop  insect  investigations. 

F.  M.  Webster,  in  charge  of  cereal  and  forage  insect  investigations. 

A.  L.  Quaintance,  in  charge  of  deciduous  fruit  insect  investigations. 

E.  F.  Phillips,  in  charge  of  bee  culture. 

D.  M.  Rogers,  in  charge  of  preventing  spread  of  moths , field  work. 

Rolla  P.  Currie,  in  charge  of  editorial  work. 

Mabel  Colcord,  librarian. 

Truck-Crop  and  Stored  Product  Insect  Investigations. 

F.  H.  Chittenden,  in  charge. 

H.  M.  Russell,  C.  H.  Popenoe,  D.  K.  McMillan,  H;  O.  Marsh,  E.  G.  Smyth, 
Thos.  H.  Jones,  agents  and  experts. 

E.  D.  Ball,®  special  field  agent. 

E.  G.  Titus,®  I.  J.  Condit,  H.  S.  Heller, & W.  B.  Parker,  collaborators. 


® Resigned  June  30,  1909 


b Resigned  January  31, 1910. 


LETTER  OF  TRANSMITTAL. 


U.  S.  Department  of  Agriculture, 

Bureau  of  Entomology, 
Washington , D.  C.,  January  25,  1910. 

Sir:  I have  the  honor  to  transmit  herewith,  for  publication  as 
Bulletin  No.  66,  seven  papers  dealing  with  certain  insects  injurious 
to  truck  crops.  These  papers,  which  were  issued  separately  during 
the  years  1907  and  1909,  are  as  follows:  The  Asparagus  Miner  and 
Notes  on  the  Asparagus  Beetles,  by  F.  H.  Chittenden;  The  Water- 
Cress  Sowbug  and  the  Water-Cress  Leaf-Beetle,  by  F.  H.  Chittenden; 
The  Cranberry  Span  worm  and  the  Striped  Garden  Caterpillar,  by 
F.  H.  Chittenden;  The  Leafhoppers  of  the  Sugar  Beet  and  Their 
Relation  to  the  “Curly-Leaf ” Condition,  by  E.  D.  Ball;  The  Semi- 
tropical  Army  Worm,  by  F.  H.  Chittenden  and  H.  M.  Russell;  The 
Hop  Flea-Beetle,  by  F.  H.  Chittenden;  Miscellaneous  Notes  on 
Truck-Crop  Insects,  by  F.  H.  Chittenden. 

Respectfully, 

L.  O.  Howard, 

Entom  ologist  and  Chief  of  Bureau . 

Hon.  James  Wilson, 

Secretary  of  Agriculture . 


in 


PREFACE. 


The  present  publication  comprises  a series  of  articles  which  have 
been  issued  in  seven  parts  and  are  now  brought  together  as  a single 
bulletin.  It  relates  to  a line  of  investigations  begun  in  1896,  the 
earlier  results  of  which  were  published  in  previous  bulletins  of  the 
present  series,  in  Yearbooks  of  the  Department,  and  in  circulars  of 
the  Bureau.  The  title,  “Some  Insects  Injurious  to  Truck  Crops,” 
is  used  in  a wide  sense  and  includes  insects  injurious  to  sugar  beet, 
since  the  same  classes  of  insects  which  affect  this  important  crop  also 
attack  table  beets  and  spinach. 

The  initial  article  is  the  first  treatment  that  has  been  given  to  the 
asparagus  miner  in  a Government  publication.  The  second  article,, 
entitled  “Notes  on  the  asparagus  beetles,”  is  a sequel  to  a general 
article  on  the  asparagus  beetles  which  appeared  in  the  Yearbook  for 
1896.  It  places  on  record  all  important  new  localities  to  date,  and 
furnishes  similarly  the  latest  information  in  regard  to  remedies.  The 
importance  which  has  been  assumed  by  the  water-cress  sowbug  since 
1902  has  necessitated  the  preparation  of  a publication  covering  this 
species,  with  suggestions  for  its  control.  The  subject  of  water-cress 
insects  has  never  been  considered  in  a Department  publication  hith- 
erto, and  similar  treatment  of  the  water-cress  leaf-beetle  to  that 
furnished  on  the  sowbug  follows.  The  cranberry  spanworm  is  given 
monographic  treatment  not  hitherto  furnished  for  it.  It  is  an  omniv- 
orous feeder,  and  has  attracted  attention  on  various  crops,  and 
especially  on  asparagus  and  strawberry.  A similar  article  on  the 
striped  garden  caterpillar,  also  an  omnivorous  form,  completes 
Part  III  of  the  bulletin. 

The  article  representing  Part  IY  is  a detailed  consideration  of  the 
sugar-beet  leafhopper  and  of  other  affiliated  species  in  their  relation 
to  the  “curly-leaf  ” condition  of  the  sugar  beet.  It  was  prepared  by 
Dr.  E.  D.  Ball,  while  special  field  agent  of  this  Bureau  in  Utah;  he 
has  been  engaged  on  this  work  for  a number  of  years.  The  semi- 
tropical  army  worm  is  the  subject  of  Part  V.  It  was  the  most  trouble- 
some insect  on  truck  crops  in  Florida  during  1907,  and  was  given 
detailed  study  from  every  possible  standpoint  by  the  authors.  In  the 
experiments  with  remedies,  which  were  conducted  by  the  junior 


v 


VI 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


author,  Mr.  H.  M.  Russell,  a series  of  15  trials  was  performed,  proving 
that  a spray  of  arsenate  of  lead  is  far  superior  to  Paris  green  under  local 
conditions.  The  final  article  of  the  series,  entitled  “The  hop  flea- 
beetle,”  has  been  a subject  of  study  for  a number  of  years.  Its 
treatment  is  monographic  to  date,  and,  while  some  of  the  data  fur- 
nished are  preliminary  in  character,  it  will  constitute  a basis  for  future 
work  on  the  same  species.  This  insect  is  given  the  name  of  flea-beetle 
because  of  the  local  name,  “hop  flea,”  used  in  the  hop-growing  region 
of  the  Pacific  coast,  but  it  is  also  a pest  in  sugar-beet  fields  and  injuri- 
ous to  rhubarb,  radishes,  and  other  truck  crops.  In  the  preparation 
of  the  article  the  writer  has  been  fortunate  in  obtaining  the  coopera- 
tion of  various  experts,  including,  particularly,  Messrs.  H.  J.  Quayle 
and  Theodor  Eder. 

Following  this  article  are  a few  miscellaneous  notes  on  truck-crop 
insects,  the  first  two  giving  additional  information  in  regard  to  the 
principal  asparagus  pests  treated  in  Part  I,  the  last  furnishing  addi- 
tional observations  on  the  water-cress  insects  treated  in  Part  II,  with 
notes  on  the  first  injurious  occurrence  of  the  destructive  pea  moth 
and  of  a western  root-maggot  in  the  United  States. 

F.  H.  Chittenden. 


CONTENTS." 


Tage, 

The  asparagus  miner  ( Agromyza  simplex  Loew) .F.  II.  Chittenden. . 1 

Descriptive 1 

Distribution 2' 

Historical  and  biological  notes 2 

Recent  injury 3* 

Remedial  measures 4 

Notes  on  the  asparagus  beetles F.  H.  Chittenden. . 6 

The  common  asparagus  beetle  ( Crioceris  asparagi  L.) 6 

The  twelve-spotted  asparagus  beetle  ( Crioceris  12-punctata  L.) 9 

The  water-cress  sowbug  ( Mancasellus  brachyurus  Harger) . . ..F.  H.  Chittenden. . 11 

Descriptive 11 

Reports  of  injurious  occurrence 12 

Methods  of  control 12 

The  water-cress  leaf-beetle  ( Phxdon  xruginosa  Suffr.) F.  H.  Chittenden. . 16 

Injurious  occurrence 16 

Descriptive 16 

Literature 18 

Habits  of  this  and  a related  species 18 

Methods  of  control 19 

The  cranberry  span  worm  ( Cleora  pampinaria  Guen.) F.  H.  Chittenden. . 21 

Descriptive 21 

Distribution 23 

Biologic  literature 24 

Unpublished  office  notes 25 

List  of  food  plants 25 

The  insect’s  life  history 26 

Natural  enemies 26 

Remedies 26 

Bibliography 27 

The  striped  garden  caterpillar  ( Mamestra  legitima  Grote) F.  H.  Chittenden. . 28 

Descriptive 28 

Biologic  notes 29' 

Natural  enemies 31 

Summary  of  habits. 32 

Methods  of  control 32 

The  leafhoppers  of  the  sugar  beet  and  their  relation  to  the  “curly-leaf  ” condi- 
tion  E.  D.  Ball..  33 

Introduction 33 

The  beet  leafhopper  ( Eutettix  tenella  Baker) 35 

Descriptive 35 

Food  plants 35 

Distribution 36 

Life  history  studies 36 

Economic  relations 41 

Economic  summary  and  proposed  remedies 47 

Bibliographical  references 48 


a The  seven  papers  constituting  this  bulletin  were  issued  in  separate  form  on  March 
16,  April  23,  and  August  31,  1907,  and  on  January  27,  January  28,  May  8,  and  July  19> 
1909,  respectively. 

27518— Bull.  66—10 2 


vn 


VIII 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


The  leafhoppers  of  the  sugar  beet  and  their  relation  to  the  “ curly-leaf  ’ ’ con- 
dition— Continued.  Page. 

Other  leafhoppers 49 

Eutettix  strobi  Fitch 49 

Eutettix  scitula  Ball 49 

Eutettix  seminuda  Say 50 

Eutettix  clarivida  Van  Duzee 50 

Eutettix  insana  Ball,  E.  albida  Ball,  and  E.  pauperculata  Ball 50 

Eutettix  stricta  Ball 50 

Agallia  sanguinolenta  Prov 51 

Agallia  cinerea  Osborn  and  Ball 51 

Agallia  bigelovix  Baker 51 

Agallia  quadripunctata  Prov.  and  A.  novella  Say 51 

Empoasca  sp 51 

Conclusions  in  regard  to  “curly-leaf” 52 

The  semi  tropical  army  worm  ( Prodenia  eridania  Cram.). 

F.  E.  Chittenden  and  E.  M.  Russell. . 53 

Introduction 53 

Descriptive 54 

Origin  and  distribution 57 

Literature  and  history 57 

Recent  injuries  and  biologic  notes 58 

Early  records 62 

Life-cycle  periods  and  generations 62 

Natural  enemies 63 

Methods  of  control 65 

Resume  of  experiments  and  conclusions 68 

Summary 69 

Bibliographical  list 70 

The  hop  flea-beetle  ( Psylliodes  punctulata  Melsh.) . . . , F.  E.  Chittenden . . 71 

Introductory 71 

Descriptive 72 

Distribution 73 

Recent  injuries * 73 

Methods  of  attack,  food  habits,  and  generations 76 

Life  history  and  habits 79 

Notes  on  other  species 81 

Local  conditions  and  natural  influences 82 

Methods  of  control 83 

Arseni  cals 83 

Contact  sprays 85 

Bordeaux  mixture 87 

Mechanical  and  cultural  methods 87 

Literature 91 

Bibliography 91 

Summary 92 

Miscellaneous  notes  on  truck  crop  insects F.  //.  Chittenden . . 93 

Successful  use  of  arsenate  of  lead  against  the  asparagus  beetle 93 

A note  on  the  asparagus  miner 94 

Injurious  occurrence  of  the  pea  moth  in  the  United  States 95 

A new  western  root-maggot 95 

Notes  on  water-cress  insects 96 

Index 99 


ILLUSTRATIONS. 


PLATES. 

Page. 

Plate  I.  Leafhoppers  (Eutettix  spp.)  and  their  work.  Fig.  1. — Eutettix 
tenella:  a,  Adult;  &,  nymph;  c,  wing;  d,  e,  genitalia;  /,  eggs 
(greatly  enlarged);  g,  section  of  beet  stem,  showing  fresh  eggs  in 
place;  h,  same,  showing  eggs  ready  to  hatch;  i,  old  egg  scars  on  beet 
stems;  j,  small  leaf  of  sugar  beet,  showing  characteristic  “curly- 
leaf  ” condition;  lc,  enlarged  section  of  back  of  an  extreme  case  of 
“ curl y-leaf,”  showing  “warty”  condition  of  veins.  Fig.  2. — Eu- 
tettix strobi:  a,  Work  of  nymphs  on  lamb’s-quarters;  6,  work  of 
nymphs  on  sugar  beet.  Fig.  3. — Eutettix  scitula:  Adult.  Fig.  4.- — 
Eutettix  clarivida:  a , Wing;  6,  head  and  pronotum;  c,  d,  genitalia. 

Fig.  5. — Eutettix  nigridorsum:  Work  of  nymphs  on  leaf  of  Helian- 
thus.  Fig.  6. — Eutettix  straminea:  Work  of  nymphs  on  leaf  of 
another  Helian thus.  Fig.  7. — Eutettix insana:  Wing.  Fig.  8.— Eu- 
tettix stricta:  a,  b,  Genitalia 34 

II.  Work  of  Eutettix  tenella  on  sugar  beet.  Fig.  1. — Three  “ curl  y-leaf  ” 
beets,  the  result  of  attack  by  Eutettix  tenella , and  one  normal  beet 
from  the  same  field,  showing  difference  in  size.  Figs.  2,  3. — 
“Curly-leaf”  beets  as  seen  in  the  field.  Fig.  4. — Normal  beets 
from  same  field 44 

III.  Work  of  Eutettix  tenella  on  sugar  beet.  Fig.  1. — A large  beet  becom- 

ing “curly.”  Fig.  2. — Back  of  a leaf  affected  by  “curly-leaf,” 
showing  “warty”  condition  and  curled  edges 44 

IV.  Work  of  Eutettix  tenella  on  sugar  beet.  Fig.  1.— A field  of  beets  de- 

stroyed by  “curly-leaf.”  Figs.  2,  3. — Cages  used  in  the  life-his- 
tory experiments 46 

V.  Spraying  apparatus  used  in  hopyards  in  British  Columbia 84 

VI.  View  of  hopyard,  showing  sheep  keeping  down  weeds 88 

VII.  Method  of  capturing  hop  flea-beetles  on  tarred  horse-sledges 90 

TEXT  FIGURES. 

Fig.  1.  The  asparagus  miner  ( Agromyza  simplex):  Fly 1 

2.  The  asparagus  miner:  Larva,  pupa,  work 2 

3.  The  water-cress  sowbug  ( Mancasellus  brachyurus) 12 

4.  Cross  section  of  cress  pond,  showing  arrangement  for  avoiding  damage 

by  water-cress  sowbug 13 

5.  The  water-cress  leaf-beetle  ( Phsedon  aeruginosa ):  Larva,  pupa,  adult 17 

6.  The  cranberry  spanworm  ( Cleora  pampinaria ):  Moth,  larva,  and  pupa. . 22 

7.  The  striped  garden  caterpillar  ( Mamestra  legitima ):  Moth,  larva,  and 

pupa 29 

8.  The  semitropical  army  worm  ( Prodenia  eridania):  Moth,  egg,  egg-mass, 

larvae 54 


IX 


X 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Page. 

JFig.  9.  The  semitropical  army  worm:  Work  of  larvae  on  “careless  weed”,  in 

potato  field 59 

10.  The  semitropical  army  worm:  Field  of  late  Irish  potatoes,  showing 

vines  entirely  stripped  by  larvae 60 

11.  The  semitropical  army  worm:  Larvae  eating  bark  of  “careless  weed;” 

also  nymph  of  spined  soldier-bug  ( Podisus  maculiventris) , predaceous 
on  larvae  of  Prodenin  cridania 61 

12.  Hop  flea-beetle  ( Psylliodes  puncfulata):  Larva  and  adult 72 

13.  View  of  hopyard,  showing  how  flea-beetles  keep  down  vines 76 

14.  Hop  leaves,  showing  work  of  flea-beetle 77 

15.  Work  of  flea-beetle  after  vines  are  grown 78 

16.  Trained  hop  shoots  stripped  by  flea-beetle 79 

17.  Breeding  and  control  cage  in  place  over  a hill 80 

18.  A crew  spraying  hops  in  British  Columbia 86 

19.  Tarred  catchers  for  hop  flea-beetles 89 

ERRATA 


Page  2,  line  19,  for  1861  read  1869. 

Page  2,  footnote0,  for  160  read  46. 

Page  18,  line  11,  for  1893  read  1903. 

Page  18,  line  22,  for  letter  read  latter. 

Page  65,  line  15  from  bottom,  for  fresh  air-slaked  read  freshly  slaked. 
Page  68,  line  8,  for  6 read  50. 


INDEX 


Page. 

, . , 70 

Actinotia  derupta,  bibliographic  reference. . - - - 50-51 

Agallia  bigelovise  on  sea-blite  (Dondia) 50-51 

sugar  beet ----- 50_51 

cincrea  on  sugar  beet - - * * * ' 52 

novella  on  sugar  beet,  habits. - 

quadripunctata  on  sugar  beet,  habits.... 50-51 

sanguinolenta  on  sugar  beet - 50-51 

uhleri  on  sugar  beet — - - - - - ^-5 

Agromyza  simplex - * 2-3 

biological  notes 2_2 

descriptive ---- 2 

distribution 2_3 

historical  notes - ^_4 

TnCpkragus  in  Cauiom^'tocimsetts,  and  Virginia 9t 

remedial  measures - 49 

Allygus  sp.,  oi  Bruner,  probably  Eutettic  ^ '53’ 58-60, 62, 69 

Amaranth,  spiny,  food  plant  of  Prodema  eridama 

Amaranthus  spinosus.  ( See  Amaranth,  spiny.)  77 

grxcians , food  plant  of  Psylliodes  punctulata 

retroflexus , food  plant  of  Psylliodes  punctulata  ... 

Avateticus  ( Eupodisus ) mucronatus , enemy  of  Prodema  eridama g0 

Aplixreta  sp.,  parasite  of  Pegomya  planipalpis.  ------ 63 

Aphiochxta  nigriceps  eating  pupa?  of  Prodema  eridama 24  25 

Apple,  food  plant  of  Cleora  pampinana ’ 51 

Empoasca 

Army  worm,  semitropical.  (See  Prodema  eridama.)  8_9  93_94 

Arsenate  of  lead  against  common  asparagus  beetle ’ 26_27 

cranberry  spanworm. 83^5, 87, 92 

hop  flea-beetle fi5_g9 

semitropical  army  worm. . - 39 

striped  garden  caterpillar ----- “ 

and  Bordeaux  mixture  against  hop  flea-beetle. . - - ----- 

striped  garden  caterpillar oz 

resin-fishoil  soap  against  hop  flea-beetle. . 83-84 

soap  against  common  asparagus  beetle ° 

Arsenite  of  copper,  adhesive,  against  semitropical  army  worm ° 69 

analysis  - .^. ......  83>g5 

lime  with  soda  against  hop  flea-beetle 

Asclepias  incarnata.  ( See  Milkweed.) 

Asparagus  beetle,  common.  (See  Crioceris  asparagi.) 

twelve  spotted.  (See  Crioceris  12-punclata.) 
beetles,  notes  on  distribution  and  destructive  occurrences ^ 


100  SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 

Page. 

Asparagus,  food  plant  of  Agromyza  simplex 1-5 

Clcora  pampinaria 21,  25 

Crioceris  asparagi 6-8 

12 -punctata 9 

Mamestra  legitima 28-32 

miner.  (See  Agromyza  simplex.) 

Atriplex  confer tifolia,  food  plant  of  Eutettix  clarivida 50 

insana 50 

pauperculata 50 

tenella 35 

food  plants  of  Eutettix  albida 50 

Ball,  E.  D.,  paper,  The  Leafhoppers  of  the  Sugar  Beet  and  their  Relation  to 

the  “ Curly-leaf  ” Condition 33-52 

Beet,  food  plant  of  Eutettix  seminuda 50 

Prodenia  eridania 61 

Psylliodes  punctulata 77,  79 

leafhopper.  (See  Eutettix  tenella.) 

sugar,  “curly-leaf”  condition  with  relation  to  Eutettix  tenella 33-48,52 

leafhoppers 33-52 

food  plant  of  Agalliof  bigelovix 50-51 

cinerea 50-51 

novella 51 

quadripunctata 51 

sanguinolenta 50-51 

uhleri 50-51 

Empoasca 51-52 

Eutettix  clarivida 50 

scitula 44-45,  49-50 

strobi 44-45,49 

tenella 35 

Psylliodes  punctulata 71,  74-77,  92 

Blackberry,  food  plant  of  Cleora  pampinaria 24,  25 

Mamestra  legitima 30,  32 

“Blackjack.  ” (See  Plnxdon  betulx.) 

“ Blight”  of  sugar  beet,  characteristics 44-46 

relation  to  leafhoppers 33-52 

or  “curly-leaf”  of  sugar  beet  around  Spreckels,  Cal.,  not  work  of 

Eutettix  tenella 46 

“Blue  beetle.”  (See  Phxdon  armoracix.) 

Boards,  tarred,  against  hop  flea-beetle 83,  88-89 

Boarmia  collecta=  Cleora  pampinaria 22 

fraudulentaria=  Cleora  pampinaria 22 

frugallaria , bibliographic  reference 27 

= Cleora  pampinaria 22 

pampinaria,  bibliographic  reference 27 

= Cleora  pampinaria 24 

sublunaria,  bibliographic  reference 27 

= Cleora  pampinaria 22 

Bordeaux  mixture,  deterrent  against  hop  flea-beetle 87,  92 

with  arsenate  of  lead  against  hop  flea-beetle 83-84 

striped  garden  caterpillar. ...  32 

Paris  green  against  hop  flea-beetle 83-85 

Bursa  bursa- pas  tor  is,  food  plant  of  Psylliodes  convexior 81 


INDEX. 


101 


Page. 

Cabbage,  food  plant  of  Mamestra  legitima 30,  32 

Phxdon  armoracix 18 

Prodenia  eridania 61 

ornithogalli 30 

Psylliodes  punctulata 77 

Callitricha  verna , food  plant  of  Phxdon  armoracix 19 

Calosoma  sayi,  enemy  of  Prodenia  eridania 64 

Cardamine  amara,  food  plant  of  Phxdon  armoracix 19 

“Careless  weed.”  ( See  Amaranth,  spiny.) 

Carp,  suggested  use  against  water-cress  sowbug 15 

Carrots,  food  plant  of  Prodenia, eridania 61 

Castor-oil  plant,  food  plant  of  Prodenia  eridania 60 

Catfish  of  no  avail  against  water-cress  leaf-beetle 20 

suggested  use  against  water-cress  sowbug 15 

“Chalcidian”  parasite  of  Psylliodes  punctulata  recorded  by  Fitch 82-83 

Chelonus  sp.,  parasite  of  Prodenia  eridania. 63 

Chenopodium  album , food  plant  of  Eutettix  strobi 49 

Psylliodes  punctulata 76 

food  plant  of  Eutettix  scitula 44-45,  49-50 

strobi 44-45 

Psylliodes  punctulata 77 

rurale,  food  plant  of  Psylliodes  punctulata 76 

Chittenden,  F.  H.,  and  Russell,  H.  M.,  paper,  “The  Semitropical  Army  Worm 

(Prodenia  eridania  Cram.)”. . . 53-70 

paper,  “Miscellaneous  Notes  on  Truck-crop  Insects” 93-97 

“Notes  on  the  Asparagus  Beetles” 6-10 

“The  Asparagus  Miner  (Agromyza  simplex  Loew)”..  1-5 
“The  Cranberry  Span  worm  ( Cleora  pampinaria 

Guen.)” 21-27 

“The  Hop  Flea-beetle  (Psylliodes  punctulataMelsh..y,  71-92 
“The  Striped  Garden  Caterpillar  (Mamestra  legitima 

Grote)” 28-32 

“The  Water-cress  Leaf-Beetle  (Phxdon  xruginosa 

Suffr.)” 16-20 

“The  Water-cress  Sowbug  (Mancasellus  brachyurus 

Harger)” 11-15 

Chlorid  of  lime,  suggested  remedy  against  water-cress  sowbug 14 

Chortophila  planipalpis—Pegomya  planipalpis 96 

Clean  cultivation  against  hop  flea-beetle 89-91,  92 

Cleora  pampinaria 21-27 

bibliography 27 

biologic  literature 24 

descriptive 21-23 

distribution : 23-24 

food  plants 25-26 

larva,  description 22 

• life  history 26 

moth,  description 21-22 

natural  enemies 26 

pupa,  description 23 

remedies 26-27 

synonyms 22 

unpublished  office  notes 25 


102 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Page. 

Cleora , tinctaria—  Cleora  pampinaria 22 

Clover,  red,  food  plant  of  Cleora  pampinaria 25 

Psylliodes  punctulata 77, 79 

white,  food  plant  of  Psylliodes  punctulata 77,  79 

Cochlearia  armoracia , food  plant  of  Phxdon  armoradx 19 

Collards,  food  plant  of  Mamestra  legitima 30,  32 

Prodenia  eridania 53,  69 

ornithogalli 30 

Cotton  cutworm.  (See  Prodenia  ornithogalli.) 

food  plant  of  Cleora  pampinaria 24-26 

Cowpeas,  food  plant  of  Prodenia  eridania 53,  60,  69 

Cranberry,  food  plant  of  Cleora  pampinaria 21,  24,  25 

spanworm.  (See  Cleora  pampinaria.) 

Cress,  food  plant  of  Phxdon  armoradx 18 

water.  ( See  Water  cress.) 

Crioceris  asparagi 6-9 

control  with  arsenate  of  lead 93-94 

remedies 8-9 

12-punctata 9-10 

larva,  young,  description 10 

Crucifers,  preferred  food  plants  of  Psylliodes 81 

Cucumber,  food  plant  of  Psylliodes  punctulata 77 

Cultural  methods  against  beet  leafhopper 48 

hop  flea-beetle 87-91 

“Curly-leaf”  of  sugar  beet  around  Spreckels,  Cal.,  not  work  of  Eutettix  ten- 

ella 46,51-52 

characteristics 44-46 

conclusions 52 

relation  to  Eutettix  tenella 33-48,  52 

leafhoppers 33-52 

Cutworm,  cotton.  (See  Prodenia  ornithogalli.) 

Cymatophora  pampinaria , bibliographic  reference 27 

—Cleora  pampinaria 22 

Deromyia  ternata , enemy  of  Polistes  annularis 64 

Dissosteira  Carolina  affected  by  fungus ^ 31 

Dock,  food  plant  of  Psylliodes  punctulata 77,  79 

Dondia,  food  plant  of  Agallia  higelovix 51 

Eutettix  tenella 35 

Ducks  against  water-cress  sowbug 14 

suggested  remedy  against  water-cress  leaf-beetle 20 

Dyar,  H.  G.,  technical  description  of  the  egg  and  larval  stages  of  Prodenia 

eridania 55-57 

Eggplant,  food  plant  of  Prodenia  eridania •. . . 53,  62,  69 

Empoasca,  association  with  so-called  “curly-leaf”  of  sugar  beet  at  Spreckels, 

Cal 46,51-52 

on  sugar  beet,  habits,  remedy 51-52 

Ernpusa  sp.,  fungous  enemy  of  Prodenia  eridania 65 

Enarmonia  nigricana , injurious  occurrence  in  United  States 95 

Entomophthora  sphxrosperma , fungous  enemy  of  Phxdon  xruginnsa 96 

Epitrix,  host  of  Perilitus  schwarzii  (?) 82 

Estigrnene  ( Leucarctia ) acrxa  affected  by  fungus 31 

Eutettix  albida  on  Atriplex 50 

dari.vida  on  sugar  beet,  appearance  and  habits 50 


INDEX,. 


103 


Page. 

Eutettix  insana  on  Atriplex 50 

nigridorsum  on  Helianthus,  discoloration  and  distortion  of  leaves  re- 
sulting  44-45 

Ipauperculata  on  Atriplex 50 

8citula  on  Chenopodium  and  sugar  beet,  discoloration  and  distortion  of 

leaves  resulting 44-45 

sugar  beet,  appearance  and  habits 49-50 

seminuda  on  beet,  appearance  and  habits 50 

straminea  on  Helianthus,  discoloration  and  distortion  of  leaves  result- 
ing  44-45 

stricta,  bibliographic  reference 48 

near  relative  of  Eutettix  tenella ' 50 

strobi , habits 44-46 

on  Chenopodium  and  sugar  beet,  discoloration  and  distortion  of 

leaves  resulting 44-45 

sugar  beet,  appearance  and  habits 49 

tenella,  adult,  description 35 

at  Lehi,  Utah 36-37,  38-40 

Maroni  and  in  the  Cache  Valley,  Utah 38 

Monroe,  Utah 38 

bibliographic  references 48 

cage  experiments,  Lehi,  Utah..... 38-40 

descriptive 35 

distribution 36 

economic  relations 41-47 

summary 47-48 

eggs,  description 35 

food  plants 35 

in  Oregon,  Idaho,  and  California 46-47 

life-history  studies 36-40 

summary 40 

nymphs,  description 35 

relation  to  “curly-leaf  ” condition  of  sugar  beet 33-48, 52 

remedies,  proposed ...  47-48 

Exorista  boarmiae,  parasite  of  Cleora  pampinaria. 26 

Fertilizers  against  hop  flea-beetle 88 

Fish  against  water-cress  sowbug 14-15 

suggested  remedy  against  water-cress  leaf-beetle. 20 

Flea-beetle,  hop.  (See  Psylliodes  punctulata.) 

European.  (See  Psylliodes  attenuata.) 
potato,  European.  (See  Psylliodes  affinis.) 
punctulated.  (See  Psylliodes  punctulata.) 
rhubarb.  (See  Psylliodes  punctulata.) 
small-punctured.  (See  Psylliodes  punctulata.) 

“Flea,”  name  for  Psylliodes  punctulata  in  the  West 71 

Fundulus  diaphanus,  F.  dispar , and  F.  notatus , suggested  use  against  water- 
cress sowbug 15 

Fungous  disease  of  Prodenia  eridania 65 

diseases  of  Mamestra  legitima 31 

enemy  of  Phsedon  aeruginosa 96 

Garden  caterpillar,  striped.  (See  Mamestra  legitima.) 

Geranium,  food  plant  of  Cleora  pampinaria. 24,  25 

Goldenrod,  food  plant  of  Mamestra  legitima 30,  32 


104 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Page. 

Grass,  food  plant  of  Mamestra  legitima 32 

Grease  wood.  ( See  Sarcobatus.) 

Guava,  food  plant  of  Cleora  pampinaria 25 

Ealtica  punctulata,  bibliographic  reference 91 

Helianthus,  food  plant  of  Eutettix  niyridorsum 44-45 

straminea 44-45 

Hickory,  food  plant  of  Cleora  pampinaria.  j 25 

Honey  locust,  food  plant  of  Cleora  pampinaria 25 

Hop  flea-beetle.  (See  Psylliodes  punctulata.) 

European.  (See  Psylliodes  attenuata.) 

“Hop-flea,”  name  for  Psylliodes  punctulata  in  the  West 71 

“Hopper-dozer.”  (See  Tar  pan.) 

“Hopperettes.”  (See  Tarred  catchers.) 

Hop  plant,  food  plant  of  Psylliodes  punctulata 71-92 

Horseradish,  food  plant  of  Plnxdon  armoracix 19 

“Ichneumon,”  parasite  of  Prodenia  eridania 58,64 

Irrigation  against  beet  leafhopper 48 

hop  flea-beetle 88 

as  affecting  “curly-leaf ’’  condition  of  sugar  beet 41-43 

Kerosene  emulsion  against  beet  leafhopper 43, 47-48 

Empoasca  on  potatoes 52 

hop  flea-beetle 85-87,  92 

Killifishes,  fresh  water.  (See  Fundulus  diaphanus,  F.  dispar , and  F.  notatus.) 

Kohlrabi,  food  plant  of  Phaedon  armoracix 18 

Lamb’s-quarters.  ( See  Chenopodium.) 

Leaf-beetle,  water-cress.  (See  Phxdon  xruginosa.) 

Leafhopper,  beet.  (See  Eutettix  tenella.) 

Leafhoppers  and  their  relation  to  “curly-leaf”  condition  of  sugar  beet 33-52 

Leucania  nigrofascia,  bibliographic  reference 70 

Lime,  air-slaked,  with  Paris  green,  against  hop  flea-beetle 83 

remedy  against  water-cress  sowbug,  burns  cress 97 

Limnerium  sp.,  parasite  of  Prodenia  eridania 63 

Locust,  Carolina.  (See  Dissosteira  Carolina.) 

Mamestra  legitima 28-32 

biologic  notes 29-31 

control  methods , 32 

descriptive 28-29 

habits,  summary 32 

larva,  description 28-29 

moth,  description 28 

natural  enemies 31 

pupa,  description 29 

Ma.ncasellus  brachyurus 11-15 

control  methods 12-15, 97 

descriptive 11-12 

injuries  and  remedies 97 

injurious  occurrences 12 

Mangel,  food  plant  of  Psylliodes  punctulata 79 

Mechanical  methods  against  hop  flea-beetle • 87-89 

Melcorus  sp.,  host  of  Spilochalcis  spp 63 

parasite  of  Prodenia  eridania 63 

Milkweed,  food  plant  of  Mamestra  legitima 30, 32 


INDEX. 


105 


Page. 

Mustard  beetle.  (See  Phxdon  armoracix  and  P.  betulx.) 

common  black,  food  plant  of  Psylliodes  punctulata 74-75,77 

food  plant  of  Phxdon  armoracix 18 

Psylliodes  punctulata 77 

hedge,  food  plant  of  Psylliodes  punctulata 74-75,  77 

white,  food  plant  of  Phxdon  betulx 97 

Nasturtium  officinale.  ( See  Water-cress.) 

Nettle,  food  plant  of  Psylliodes  punctulata 77,  79 

Noctua  xylina , bibliographic  reference 27 

Okra,  food  plant  of  Prodenia  eridania 53,  69 

Ophion  tityri , parasite  of  Prodenia  eridania 63 

Orange,  food  plant  of  Cleora  pampinaria 25 

Paris  green  against  common  asparagus  beetle 8 

cranberry  span  worm 26-27 

hop  flea-beetle 83-85, 87, 92 

semitropical  army  worm 65-69 

striped  garden  caterpillar 32 

and  Bordeaux  mixture  against  hop  flea-beetle 83-85 

flour  against  water-cress  leaf-beetle 19 

plaster  or  air-slaked  lime  against  water-cress  leaf-beetle 19 

water  against  water-cress  leaf-beetle 19 

dry,  with  air-slaked  lime,  against  hop  flea-beetle 84-85 

Pea  moth.  (See  Enarmonia  nigricana.) 

Pear,  food  plant  of  Cleora  pampinaria 24,  25 

Peas,  food  plant  of  Enarmonia  nigricana 95 

Mamestra  legitima 28,  30,  32 

Prodenia  ornithogalli 30 

Pegomya  planipalpis  on  radish 95-96 

Pepper,  food  plant  of  Prodenia  eridania 53,  69 

Perilitus  schwarzii  (f),  parasite  of  Epitrix 82 

Phyllotreta 82 

Psylliodes  punctulata 82 

Phxdon  xruginosa 16-20 

beetle,  description 16-17 

control  methods 19-20 

descriptive 16-18 

egg,  description 17 

fungous  enemy 96 

habits 18-19 

injurious  occurrence 16 

larva,  description 17 

literature 18 

Plagiodera  viridis  a synonym 18 

pupa,  description . . . 18 

armoracix , habits 18-19 

synonyms 18 

betulx= Phxdon  armoracix 18-19 

on  white  mustard 97 

cochlearix  Fab.,  distinct  from  Phxdon  armoracix 18 

Phalxna  phytolaccx,  bibliographic  reference 70 

= Prodenia  eridania 57 

Phlepsius  irroratus,  mistaken  determination  of  Eutettix  sirobi 49 


106  SOME  INSECTS  INJUBTOUS  TO  TRUCK  CROPS. 

Page. 

Phyllotreta,  host  of  Perilitus  schwarzii  (?) 82 

Phytolacca  decandr a.  ( See  Pokeweed.) 

Pigweed.  (See  also  Amaranihus  retrofexus.) 

food  plant  of  Psylliodes  punctulata 79 

Plagiodera  cochle arise  Panz.,  Gy\\.=Phxdon  armoracise 18 

viridis=Phsedon  seruginosa 18 

Podisus  maculiventris,  enemy  of  Prodenia  eridania 64 

Pokeweed,  food  plant  of  Prodenia  eridania 53, 58, 61-62,  69 

moth,  name  for  Prodenia  eridania 57 

Polistes  annularis,  enemy  of  Prodenia  eridania 64 

Polypeza  sp.,  parasite  of  Pegomya  planipalpis 96 

Pontia  rapse,  enemy  of  Prodenia  eridania 64 

Potato  flea-beetle,  European.  (See  Psylliodes  affinis .) 

food  plant  of  Prodenia  eridania 53,  58-59,  69 

Psylliodes  punctulata 77,  79 

“Pretty  cutworm,”  manuscript  name  for  Mamestra  legitima 30-31 

Prodenia  eridania 53-70 

bibliographic  list 70 

control  methods 65-69 

descriptive 54-57 

distribution 57 

early  records 62 

egg,  description 54 

fungous  disease 65 

generations 62-63 

history 57 

injury  to  truck  crops 53-70 

larval  stages,  description 55-57 

life-cycle  periods 62-63 

literature 57-58 

moth,  description 54 

natural  enemies 63-65 

origin 57 

parasites 63 

predaceous  enemies 64-65 

Prodenia  nigrofascia  Hulst  a synonym 54 

pupa,  description 55 

summary 69 

nigrofascia  of  Hulst = Prodenia  eridania 54 

omithogalli , association  with  Mamestra  legitima  in  damage  to  garden 

crops 30 

phytolaccse,  bibliographic  reference 70 

Psylliodes  affinis,  the  European  potato  flea-beetle 81 

attenuata,  the  European  hop  flea-beetle 81 

chrysocephala  on  edible  crucifers  in  Europe,  habits 81-82 

convexior,  comparison  with  Psylliodes  punctulata 73 

on  Bursa  bursa-pastoris 81 

notes  on  various  species 81-82 

punctulata 71-92 

adult,  habits 79-80 

bibliography 91-92 

control  methods 83-91 

descriptive 72-73 


INDEX. 


10? 


Page. 

, , . 81 

Psy Modes  punctulata,  development 73 

distribution.  ...  - n 

- M;,v """"""I  ve-7? 

generations 

habits ‘ 82 

host  of  Perilitus  schwarzii  (?) 

...  , "6-10 

injuries,  recent gQ 

larva,  habits 79-8 J 

life  history ' 

literature ~ 

local  conditions  affecting  abundance ^ ^ 

methods  of  attack - 80-81 

02 

Quayle,  H.  J.,  account  of  life  history  and  habits  of  Psylliodes  punctulata 79-81 

Radish,  food  plant  of  Pegomya  planipalpis ’ ^ 

Psylliodes  punctulata g()  ^ 

Rape,  food  plant  of  Mamestra  legitima. - - * ' ' * ‘ ’ 80 

Prodenia  ornithogalli 

“Raps-erdfloh.”  (See  Psylliodes  chrysocephala.) 

Resin-fishoil  soap  with  arsenate  of  lead  against  hop  flea-beetle. . . . - - - - 

striped  garden  caterpillar. .....  oz 

soap  and  arsenate  of  lead  against  common  asparagus  beetle 8^9 

wash  against  hop  flea-beetle 

Rhubarb  flea-beetle.  (See  Psylliodes  punctulata.)  ^ ^ 

food  plant  of  Psylliodes  punctulata ’ 4g 

Rolling,  remedy  against  beet  leafhopper 87_gg 

hop  flea-beetle 95-96 

Root  maggot,  a new  one  from  the  West gj 

Rose,  food  plant  of  Empoasca. 

Xeil'H(*tDa0nd  Chittenden,  F.  H„  paper,  “ The  Semitropieal  Army  Worm  ^ 

(Prodenia  eridania  Cram.)” - 

Russian  thistle.  (See  Thistle,  Russian.)  30.32 

Ruta-baga,  food  plant  of  Mamestra  legitima ’ gQ 

Prodenia  ornithogalli 

Salt-marsh  caterpillar.  (See  Estigmene  \Leucarclia]  aerxa.) 

Sarcobatus,  food  plant  of  Eutettix  tenella 83-85 

Scheele’s  green  against  hop  flea-beetle 

Schilbeodes.  (See  Catfish.) 

Sea-blite.  (See  Dondia.)  gg, 

Semasia  nigricana=Enarmonia  nigricana 

Shad  scale.  (See  Atriplex  confertifolia.) 

Shepherds’ purse.  (See  Bursa  bursa-pastoris.)  83.88-89 

Sheets,  tarred,  against  hop  flea-beetle * 

[ Snuff,  against  hop  flea-beetle 53  60 

1 Solarium,  wild,  food  plant  of  Prodenia  eridania 

Solidago  spp.  (See  Goldenrod.) 

Sowbug,  water-cress.  (See  Mancasellus  brachyurus.) 

Spanworm,  cranberry.  (See  Cleora  pampmana.)  6g 

Spilochalcis  spp.,  parasites  of  Meteorus 

secondary  parasites  of  Prodenia  eridania 


108 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Page. 

Sporotrichum  minimum , fungous  enemy  of  Mamestra  legitima 31 

Starwort,  water.  (See  Callitricha  verna.) 

Stiretrus  anchorago,  var  diana,  enemy  of  Prodenia  eridania 64 

Strawberry,  food  plant  of  Cleora  pampinaria 21,  24,  25 

Striped  garden  caterpillar.  (See  Mamestra  legitima.) 

Sulphate  of  copper,  suggested  remedy  against  water-cress  sowbug 14 

Sweet  potato,  food  plant  of  Prodenia  eridania 53,  59-62,  69 

Tar  pan,  or  tarred  wings,  against  beet  leafhopper 48 

Tarred  catchers  against  hop  flea-beetle 88-89 

Thamnotettix  tenellus,  bibliographic  references 48 

Thistle,  Russian,  food  plant  of  Eutettix  tenella 35 

Tobacco  extract  against  hop  flea-beetle 86 

food  plant  of  Mamestra  legitima 30,  32 

powdered,  against  hop  flea-beetle 83 

Tomato,  food  plant  of  Prodenia  eridania 53, 58,  69 

Trap  crops  against  hop  flea-beetle 87, 92 

plants  in  control  of  asparagus  miner 4-5 

Truck-crop  insects,  miscellaneous  notes 93-97 

Tumbleweed.  (See  Amaranthus  grsecians.) 

Turnip,  food  plant  of  Mamestra  legitima 30,  32 

Prodenia  ornithogalli 30 

Psylliodes  punctulata 77,  79 

mined  probably  by  Pegomya  planipalpis 96 

Veronica  bcccabunga , food  plant  of  Phsedon  armoracise 19 

Verticillium,  fungous  enemy  of  Dissosteira  Carolina 31 

Estigmene  (Leucarctia)  acraea 31 

Mamestra  legitima 31 

Violet,  food  plant  of  Mamestra  legitima 30, 32 

Water-cress,  burned  by  lime  used  as  insecticide  against  sowbug 97 

food  plant  of  Mancasellus  brachyurus 11-12 

Phsedon  aeruginosa 16 

armoraciae 19 

insects,  notes 96-97 

leaf-beetle.  (See  Phaedon  aeruginosa.) 

method  of  growing  to  avoid,  damage  by  sowbug 13-14 

sowbug.  (See  Mancasellus  brachyurus.) 

Whale-oil  soap  against  hop  flea-beetle 85-87, 92 

Willow,  food  plant  of  Cleora  pampinaria 24,  25 

Winthemia  quadripustulata,  parasite  of  Prodenia  eridania 63 

Xylomiges  phytolaccae,  bibliographic  reference 70 


o 


I 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY-  BULLETIN  No.  66,  Part  I. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


THE  ASPARAGUS  MINER, 

NOTES  ON  THE  ASPARAGUS  BEETLES. 


F.  II.  CHITTENDEN,  • 


Entomologist  in  Charge  of  Breeding  Experiments. 


Issued  March  16,  1907. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1907. 


CONTENTS. 


Page. 

The  asparagus  miner  ( Agromyza  simplex  Loew) 1 

Descriptive 1 

Distribution 2 

Historical  and  biological  notes 2 

Recent  injury 3 

Remedial  measures «. 4 

Notes  on  the  asparagus  beetles 6 

The  common  asparagus  beetle  (Crioceris  asparagi  L. ) 6 

Remedies 8 

The  twelve-spotted  asparagus  beetle  ( Crioceris  12-punctata  L. ) 9 


ILLUSTRATIONS. 


Page. 

Fig.  1.  Agromyza  simplex:  Fly 1 

2.  Agromyza  simplex:  Larva,  pupa,  work 2 

hi 


Issued  March  16,  liN)?. 


B ' U.  S.  D.  A.,  B.  E.  Bui.  66,  Part  I. 

SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  ASPARAGUS  MINER. 

{Agromyza  simplex  Loew. ) 

The  stalks  of  asparagus  are  frequently  attacked  by  insects,  ana  in 
recent  years  have  been  reported  considerably  injured  by  the  larva  or 
maggot  of  a minute  black  fly  to  which  the  name  asparagus  miner  has 
been  given.  The  larva  mines  under  the  epidermis  of  the  stalk,  and 
when  it  has  transformed  to  the  puparium  or  “flaxseed”  stage  the  thin 
outer  skin  becomes  more  or  less  ruptured  and  the  presence  of  the 
insect  is  easily  detected.  It  operates  more  abundantly  near  the  base 
of  the  stalks  and  penetrates  below  the  surface  of  the  ground  to  a 
depth  of  7 or  8 inches.  During  the  year  1906  this  species  attracted 
considerable  attention  by  its  abundance  in  some  of  the  principal 
asparagus-growing  sections  of  New  England  and  it  bids  fair  to  become 
a pest  of  considerable  importance.  It  was  first  noticed  on  asparagus 


Fig.  1.— Agromyza  simplex:  Fly,  dorsal  view  at  left,  lateral  view  at  right.  Highly  magnified 

(or  ginal). 

in  1896,  ten  years  earlier  than  the  present  writing,  prior  to  which 
time  nothing  was  known  of  its  habits.  It  is  a native  species  and  evi- 
dently restricted  to  asparagus  as  a food  plant.  Until  the  year  1906 
it  had  not  been  recognized  as  doing  injury  to  cutting  beds,  although 
attack  had  been  observed  in  various  sections.  The  mines  of  the  larvae 
about  and  below  the  bases  of  the  stalks  are  frequently  so  abundant 
that  they  have  the  effect  of  girdling,  so  that  the  injured  stalks  can  be 
readily  pulled  from  the  ground. 

DESCRIPTIVE. 

The  parent  insect  is  a two- winged  fly  (fig.  1),  metallic  black,  with 
large  prominent  head  and  e}^es,  and  clear  wings,  the  wing  expanse 
being  about  one-sixth  of  an  inch  (1  mm.). 


1 


9 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


The  larva  (fig.  2,  a)  is  about  one-fifth  of  an  inch  long  and  milk- 
white  in  color.  Like  other  maggots,  it  is  footless,  large  at  the 

posterior  extremity,  and  tapering 
toward  the  head. 

The  puparium  (fig.  2,  d,  e)  is  not 
unlike  the  “flaxseed”  of  the  perni- 
cious Hessian  fly,  with  which  it  has 
been  aptly  compared.  At  a little  dis- 
tance, also,  it  suggests  a Lecanium 
scale.  This  stage  is  remarkable  be- 
cause of  its  peculiar  flattened  and 
curved  position,  as  seen  from  the 
side.  It  is  red  in  color,  and  meas- 
ures about  3.5  mm.  in  length  and 
about  1 mm.  in  width. 

The  egg  has  not  been  observed. 
This  species  belongs  to  the  dipter- 
ous family  Agromyzidae,  and  was  described  by  Loew  in  1861, a the 
locality  being  given  as  “Middle  States.” 

DISTRIBUTION. 

In  its  injurious  occurrences  this  species  appears  to  be  limited  to  the 
eastern  United  States,  from  New  England  to  Tennessee.  From  avail- 
able data  it  is  quite  obvious,  however,  that  it  may  be  destructive  over  a 
considerable  territory,  including  a large  portion  of  Massachusetts  and 
Connecticut,  Long  Island,  the  District  of  Columbia,  Pennsylvania, 
and  Tennessee.  As  it  is  recorded  from  New  Jersey,  it  is  probably 
injurious  there,  although  no  reports  of  injury  in  that  State  have 
reached  this  office.  In  time  it  will  doubtless  attract  attention  in  inter- 
mediate points  and  in  States  farther  north  and  west.  It  has  also 
appeared  in  asparagus  beds  in  California. 

HISTORICAL  AND  BIOLOGICAL  NOTES. 

In  May,  1897,  and  afterwards  this  fly  was  observed  in  abundance  by 
the  writer  on  terminal  shoots  of  asparagus,  particularly  at  Cabin 
John,  Md.  Two  weeks  later  no  more  flies  were  seen,  but  June  26 
they  reappeared  and  were  then  usually  seen  in  copula.  It  was  sur- 
mised at  the  time  that  this  second  appearance  indicated  the  first  new 
generation  of  the  j^ear  and  its  abundance  on  asparagus  seemed  to  show 
that  it  lived  in  some  manner  at  the  expense  of  that  plant.  Examination 
of  asparagus  plants  at  that  time,  however,  failed  to  show  attack.  The 
facts  which  have  just  been  narrated  were  published  in  1898. b 


Fig.  2 .—Agromyza  simplex:  a,  larva,  lateral 
view;  b,  thoracic  spiracles;  c,  anal  spiracles; 
. d,  puparium  from  side;  e,  same  from  above; 
/,  section  of  asparagus  stalk,  showing  injury 
and  location  of  puparia  on  detached  sec- 
tion; a-e,  much  enlarged;  /,  slightly  reduced 
(original). 


"Diptera  America}  septentrionalis  indigena,  Centuria  octava  84,  p.  160. 
lj  Bui.  10,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agric.,  p.  62,  1898. 


THE  ASPARAGUS  MINER. 


3 


In  1900  we  received  complaint  of  injuries  in  the  District  of  Columbia, 
and  from  Knoxville,  Tenn.,  and  in  the  meantime  the  species  came 
under  the  observation  of  Mr.  F.  A.  Sirrine,  who  has  stated  a that  work 
was  first  observed  in  asparagus  fields  on  Long  Island  in  1896.  This 
statement  is  made  in  a bulletin  of  six  pages,  which  represents  all  that 
was  known  of  the  species  at  that  time. 

Late  in  September,  1900,  word  was  received  from  Mr.  Frederic 
Voigt,  Tennallytown,  D.  C.,  of  injury  to  the  stalks  of  asparagus  on 
his  and  a neighboring  truck  farm.  When  the  writer  visited  the 
field,  however,  although  injury  was  apparent  on  the  outer  skin  of 
some  stalks,  no  living  specimens  could  be  obtained,  only  the  dried 
puparia  being  in  evidence  at  this  time.  October  2 of  the  same  year, 
Mr.  Samuel  M.  Bain,  University  of  Tennessee,  Knoxville,  Tenn.,  sent 
a stalk  of  asparagus  showing  the  work  of  this  miner  upon  the  skin, 
and,  October  27,  specimens  of  the  dried  puparia. 

February  18,  1901,  Mr.  T.  Miles  Brous,  Bustleton,  Philadelphia,  Pa., 
wrote  that  this  insect,  which  he  accurately  described,  seemed  to  cause 
much  greater  trouble  than  the  common  asparagus  beetle.  A neighbor 
had  lost  two  or  three  new  beds  of  asparagus  on  account  of  its  ravages. 

By  the  writer’s  direction,  Mr.  F.  C.  Pratt  visited  a large  truck  farm 
at  Brookland,  D.  C.,  where  asparagus  was  one  of  the  main  crops,  June 
18,  1902.  Asparagus  was  still  being  cut  for  market,  but  volunteer 
plants  were  growing  here  and  there  in  fields  of  corn,  cantaloupe,  and 
potatoes,  between  rows.  A few  flies  were  seen  on  terminal  shoots  of 
asparagus  that  showed  wilting,  and  many  volunteer  plants  were  found 
badly  infested,  most  individuals  having  transformed  to  pupge. 
Although  stems  break  off  just  below  the  ground,  the  entire  colony  of 
insects  below  that  point  is  left  with  sufficient  moisture  and  nourish- 
ment for  their  maintenance.  The  puparia  were  present  in  great 
numbers  underneath  the  outer  skin  of  the  root,  and  as  many  as  nine 
puparia  were  counted  in  a space  only  an  inch  long  on  one  stalk.  The 
stalks  below  the  point  of  injury  appeared  to  be  perfectly  sound. 
Larvae  also  were  found  in  rotting  stalks  that  broke  off  just  belowground. 

During  1905  Mr.  Ralph  E.  Smith  reported  this  species  as  becoming 
abundant  in  California,  though  not  of  any  great  importance  at  that 
time.  His  description  of  the  insects’  manner  of  work  leaves  no  doubt 
as  to  the  identit}^  of  the  species.6 

RECENT  INJURY. 

During  September,  1906,  Messrs.  J.  B.  Norton  and  A.  D.  Shamel, 
of  the  Bureau  of  Plant  Industry,  furnished  stems  of  asparagus  from 
Concord,  Mass.,  showing  severe  infestation  by  this  species,  many 


a Bui.  189,  N.  Y.  Agric.  Exp.  Sta.,  p.  277,  Geneva,  1900. 
&Bul.  165,  Univ.  of  Cal.  Agric.  Exp.  Sta.,  p.  96,  1905. 


4 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


puparia  being  present  under  the  mined  outer  skin.  In  the  neighbor- 
hood of  Concord,  a very  important  asparagus-growing  region  where 
hundreds  of  acres  are  devoted  to  this  crop,  the  infestation  was  practi- 
cally absolute,  the  insect  being  found  even  as  abundantly  as  the  common 
asparagus  beetle,  being  present  wherever  rust  was  found,  as  also  where 
no  rust  was  present.  The  specimens  submitted  were  about  the  average 
as  regards  the  degree  of  infestation,  some  plants  showing  injury  7 
inches  below  the  surface. 

Severe  injury  was  reported  on  the  farms  of  Mr.  Frank  Wheeler  and 
Mr.  Charles  W.  Prescott,  at  Concord,  Mass.  The  growers  in  that 
region  had  never  noticed  this  insect  until  Mr.  ShamePs  examination 
showed  that  its  injuries  were  extensive.  Later  Mr.  Shamel  reported 
finding  infestation  in  every  field  and  patch  of  asparagus  which  he  ■ 
visited  in  Massachusetts  and  Connecticut,  particularly  at  Suffield, 
Granby,  and  Hartford,  Conn.,  and  he  believed  attack  to  be  widespread. 

October  26,  1906,  Mr.  Ralph  E.  Smith  wrote,  by  request,  that  the 
conditions  under  which  this  asparagus  miner  was  found  in  abundance 
in  the  yellow  stalks  of  asparagus  in  California,  as  reported  by  him  in 
an  article  on  Asparagus  Rust  Control/4  had  prevailed  for  two  or  three 
years.  The  insect  was  al  ways  very  abundant  at  the  base  of  these  yellow, 
dying  stalks,  although  the  injury  was  attributed  to  the  “ centipede,” 
reported  as  wireworms  on  a previous  occasion.6 

Remedial  measures. 

Witn  our  present  knowledge  of  the  life  economy  of  this  species,  two 
methods  of  control  suggest  themselves  as  of  greatest  value,  and  it  may 
be  that  they  will  prove  all  that  is  necessary  under  ordinary  conditions. 

(1)  In  spring  permit  a few  volunteer  asparagus  plants  to  grow  as  a 
trap  crop,  to  lure  the  fly  from  the  main  crop  or  the  cutting  beds  for 
the  deposition  of  her  eggs.  After  this  has  been  accomplished  the  trap 
crop  should  be  destroyed  b}^  pulling  the  infested  plants  and  burning 
them  with  their  contained  puparia.  The  time  to  pull  the  plants  will 
vary  according  to  localit}-  and  somewhat  according  to  season  also. 
The  second  and  third  week  in  June  would  be  about  the  right  time  in 
and  near  the  District  of  Columbia.  On  Long  Island  this  work  should 
be  done  a week  or  two  later.  In  the  northernmost  range  of  this 
insect — for  example,  in  Massachusetts — the  last  of  June  and  the  first 
of  July  would  probably  be  a suitable  time. 

(2)  The  second  generation  can  be  destroyed  in  like  manner  by  pull- 
ing old  infested  asparagus  stalks  as  soon  as  attack  becomes  manifest 
and  promptly  burning  them  also. 


a Bui.  172,  Univ.  Cal.  Agric.  Exp.  Sta.,  p.  21;  &Bul.  165,  1.  c. 


THE  ASPARAGUS  MINER. 


5 


If  this  work  were  carefully  done  over  a considerable  area,  it  would 
leave  little  necessit}r  for  other  methods,  since  it  would  do  away  with 
these  insects  in  the  vicinity  and  leave  few  to  be  dealt  with  another 
season;  unless,  indeed,  this  insect  has  an  alternate  food  plant.  The 
cooperation  of  neighboring  asparagus  growers  and  thoroughness  are 
essential  for  success. 

This  method  will  operate  also  against  the  rust  which  is  now  present 
in  many  fields  infested  by  the  miner. 


NOTES  ON  THE  ASPARAGUS  BEETLES. 


Since  the  publication  of  the  writer’s  general  article  on  the  asparagus 
beetles  in  the  Yearbook  for  1896, a many  notes  on  their  distribution  and 
destructive  occurrences  have  been  published.  Some  additional  data 
were  published  soon  afterward.6  The  following  brief  review  of  the 
subject  is  submitted  as  a sequel  to  those  articles  and  a summary  of  the 
further  dissemination  of  these  pests  in  a decade  of  years. 

THE  COMMON  ASPARAGUS  BEETLE. 

( Crioceris  asparagi  L. ) 

The  predictions  made  by  the  writer  in  regard  to  the  future  distri- 
bution of  the  common  asparagus  beetle  haAre  been  completely  fulfilled 
as  regards  its  western  spread,  although  it  has  not  as  yet  been  reported 
as  far  south  as  Kentucky-.  Mr.  J.  G.  Sanders,  however,  informs  the 
writer  that  it  has  been  established  about  Columbus,  Ohio,  since  1903, 
and  Mr.  Charles  Dury,  Cincinnati,  Ohio,  reported  this  species  at  Indian 
Hill,  about  7 miles  from  that  city,  on  asparagus  beds  in  1905.  Hundreds 
were  observed  during  June.  The  customary  injury  was  noticed,  and 
plants  appeared  as  though  scorched  with  fire.  In  1897  the  species 
was  observed  to  have  continued  its  spread  westward  along  Lake  Erie, 
and  was  then  known  in  nine  counties  in  northeastern  Ohio.  The  fol- 
lowing year  it  was  first  noticed  in  western  Virginia.  In  1898  also  it 
was  reported  to  have  been  present  at  Benton  Harbor,  Mich.,  since 
1896.  By-  1899  it  had  made  its  appearance  in  Canada,  accompanied  by 
the  twelve-spotted  species,  in  the  Niagara  River  region. 

It  is  interesting  to  note  that  in  1900  the  present  species,  which  had 
been  rapidly  increasing  its  range  in  the  East,  including  New  York, 
after  occurring  in  injurious  numbers  in  Maryland,  was  apparently 
totally  destroyed  by  the  hot  spell  of  July  and  August  that  occurred 
in  the  District  of  Columbia  and  neighboring  parts  of  Virginia  and 
Maryland;  whence  the  conclusion  that  this  condition  prevailed  to  a 
considerably-  larger  extent  than  came  to  the  writer’s  personal  notice. 
In  1901  Dr.  James  Fletcher  noted  that  the  species,  though  present  in 
the  Niagara  district,  had  not  increased  to  the  extent  that  was  feared. 
It  had  spread  to  Guelph,  Ontario,  that  year,  and  did  much  damage 
about  St.  Catharines.  In  1901  its  occurrence  around  Toronto  was 


"Yearbook  U.  8.  Dept.  Agric.  f.  1896  (1897),  pp.  341-352. 

6 Bui.  10,  n.  8.,  Div.  Ent.,  U.  S.  Dept.  Agric.,  pp.  54-59,  1898. 


NOTES  ON  THE  ASPARAGUS  BEETLES. 


noticed.  It  was  reported  also  40  miles  west  of  Chicago,  111.  It  has 
become  veiy  generally  distributed  in  asparagus- growing  districts  in 
New  York  State,  and  has  reached  Glens  Falls,  which  approximates  its 
northernmost  limit  in  this  country.  In  1905  we  received  complaint 
of  this  insect  as  a pest  in  Illinois,  at  Park  Ridge,  and  of  its  occurrence 
about  Chicago.  Reports  from  Michigan  showed  that  it  had  been 
present  there  in  1904  in  the  vicinity  of  Ada,  about  10  miles  from 
Grand  Rapids,  and  that  it  was  a pest  in  that  vicinity. 

Although  the  data  given  above  indicate  that  the  species  is  now  well 
distributed  throughout  the  Upper  Austral  region,  for  some  reason  its 
occurrence  in  Indiana  has  not  yet  come  to  our  knowledge;  neverthe- 
less although  there  are  naturally  many  uninvaded  localities,  it  is 
I undoubtedly  established  in  that  State,  most  probably  near  Lake 
Michigan. 

As  an  example  of  its  manner  of  distribution,  it  might  be  noted  that 
in  May,  1905,  the  beetle  was  found  for  the  first  time  in  Warrenton, 
Fauquier  County,  Va.,  a little  farther  inland  than  it  had  ever  been 
noticed  in  that  section.  Yet  this  species  has  been  permanently  estab- 
lished in  the  adjoining  Alexandria  County  for  many  years. 

August  8, 1905,  Air.  Ralph  E.  Smith  wrote  of  the  occurrence  of  this 
species  in  California,  stating  that  during  two  seasons  it  had  been  very 
abundant  at  Bouldin  Island,  the  principal  asparagus  center  of  that- 
region.  As  Air.  Smith  was  familiar  with  this  insect  and  its  occur- 
rence on  the  Atlantic  coast,  there  is  little  doubt  that  his  identification 
is  correct.  In  the  winter  of  1904  to  1905  Bouldin  Island  was  flooded 
and  remained  under  water  for  over  a year.  It  had  just  been  reclaimed 
and  there  were  no  signs  of  the  beetles'.  There  is,  therefore,  a possibility 
that  the  insect  was  exterminated  in  that  region,  and  this  includes  the 
State,  if  the  occurrence  of  the  species  was  only  local. 

The  dying  out  of  this  asparagus  beetle  in  small  localities  where  it 
has  not  become  thoroughly  established  is  not  without  precedent,  as  its 
recorded  occurrence  at  Rock  Island,  111.,  many  years  ago,  has  been 
verified  by  specimens  now  in  a Chicago  museum,  properly  labeled 
as  collected  there  by  the  late  A.  Bolter,  an  experienced  collector  of 
Coleoptera.  indeed,  it  would  seem  that  few  vegetable-feeding  insects 
are  more  subject  to  extermination  in  a limited  locality  not  contiguous 
to  one  also  infested  than  is  the  present  species. 

October  26,  1906,  Air.  Ralph  E.  Smith,  at  the  writer’s  request, 
reported  the  status  of  this  species  in  California.  He  wrote  that  during 
the  summer  he  found  the  beetles  again,  and  that  they  were  very  abun- 
dant in  fields  near  Oakley,  Cal.  It  could  not  be  stated  that  the  insect 
was  of  general  occurrence  in  the  State,  but  apparently  it  existed  only 
in  a few  scattered  colonies.  As  previously  reported  the  colony  at 
Bouldin  Island  appears  to  have  been  exterminated  by  flood,  and 


8 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


the  Oakley  occurrence  was  the  first  that  Mr.  Smith  had  noted  since. 
In  most  of  the  asparagus  acreage  of  the  State  the  insect  was  not  yet 
present. 

Mr.  Franklin  Sherman,  jr.,  has  kept  a careful  record  of  the  occur- 
rence of  this  species  in  North  Carolina,  and  informed  the  writer,  on 
the  occasion  of  a visit  in  1906,  that  it  is  common  in  the  east-central 
part  of  the  State  in  the  trucking  belt,  and  especially  abundant  at 
Raleigh,  Wake  County,  Goldsboro,  Wayne  County,  and  Warsaw, 
Duplin  County. 

In  order  to  make  the  present  account  of  the  known  distribution  of 
this  species  as  complete  as  possible,  inquiry  was  made  of  the  official 
entomologists  of  the  States  of  Kentucky,  Iowa,  Missouri,  Nebraska, 
and  Minnesota,  all  of  whom  reported  that  the  occurrence  of  this  spe- 
cies in  their  States  had  not  been  brought  to  their  attention.  Mr.  James 
G.  Moore,  however,  assistant  in  horticulture  at  the  University  of  Wis- 
consin, Madison,  W is.,  stated  that  the  asparagus  beetle  had  been  found 
in  Wisconsin,  but  he  had  no  special  data  on  its  distribution. 

REMEDIES. 

With  regard  to  remedies  good  results  have  followed  the  experimental 
use  of  arsenate  of  lead.  This  insecticide  has  come  into  very  general 
favor  in  recent  years,  and  in  the  correspondence  of  this  office  we  have 
for  some  time  advised  its  employment  against  most  leaf-feeding  beetles, 
like  the  asparagus  beetles.  In  Connecticut  Dr.  W . E.  Britton  a has  made 
a practical  test  of  this  remedy  on  asparagus  plants,  spraying  them  from 
all  four  sides  in  succession  because  of  the  slight  leaf  exposure  as  com- 
pared with  most  other  plants.  The  day  following  treatment  (June  I) 
many  dead  beetles  and  larvse  were  found  on  and  under  the  plants.  A 
few  had  survived  and  were  feeding,  but  ten  days  later  only  a few 
living  larvse  could  be  found,  and  the  beetles  did  not  again  become 
abundant  on  the  plants  during  the  summer.  The  same  amount  of 
good  might  be  accomplished  with  scarcely  greater  expense  by  spray- 
ing from  opposite  sides  and  repeating  just  before  the  time  for  the  last 
generation  to  develop  and  in  time  to  check  the  beetles  before  they  go 
into  winter  quarters. 

In  Pennsylvania  Prof.  II.  A.  Surface,6  in  a series  of  experiments 
with  Paris  green  and  arsenate  of  lead,  applied  to  asparagus  plants  the 
first  week  of  June,  1905,  found  that  not  more  than  50  per  cent  of  the 
insects  were  killed  when  Paris  green  and  lime  were  used.  With  lead 
arsenate  90  per  cent  were  killed,  while  in  one  experiment,  by  the  addi- 
tion of  resin  soap,  which  is  used  as  an  addition  to  an  insecticide  to 

« Rept.  Conn.  Agric.  Exp.  Sta.  f.  1903  (1904),  pp.  275,  276. 

& Monthly  Bulletin,  Div.  of  Zool.,  Pa.  State  Dept.  Agric.,  Vol.  IV,  May,  1906,  p.  8. 


NOTES  ON  THE  ASPARAGUS  BEETLES. 


9 


enable  the  poison  to  adhere  better  to  smooth  plants,  100  per  cent  of 
the  insects  were  killed  on  the  50  plants  treated.  In  this  case  the 
arsenate  of  lead  was  used  at  the  rate  of  about  1 pound  to  2d  gallons  of 
water,  and  2^  pounds  of  soap  were  added. 

Arsenate  of  lead  has  been  used  with  satisfactory  results  on  asparagus 
at  the  rate  of  1 pound  in  16  to  2d  gallons  of  water.  Additional  experi- 
ments are  necessary  to  ascertain  the  exact  amount  of  the  poison  that  can 
be  used  economically  to  produce  the  best  effect.  In  Professor  Surface’s 
experiments  evidently  only  a single  spra}^  was  applied. 

THE  TWELVE-SPOTTED  ASPARAGUS  BEETLE. 

( Crioceris  12 -punctata  L. ) 

Nearly  every  year  since  1896,  when  the  distribution  of  the  twelve- 
spotted  asparagus  beetle  was  recorded  b}T  the  writer,®  the  appearance 
of  this  species  has  been  noted  in  new  localities  in  the  United  States, 
until  it  is  now  well  distributed  westward  and  especiall}7  northward. 

In  1898  Dr.  J.  B.  Smith  stated  that  it  then  occurred  throughout  the 
State  of  New  Jersey  “south  of  the  shale  from  the  Atlantic  coast  to  the 
Delaware.”  The  following  year  (1899)  it  was  recorded  by  Dr.  E.  P. 
Felt  from  different  counties  in  New  York,  and  as  far  west  as  Buffalo. 
In  some  places  the  species  was  abundant,  while  in  some  near-by  locali- 
ties it  could  not  be  found,  showing  that  it  was  still  locally  distributed 
through  New  York.  It  was  afterwards  recorded  present  in  Albany, 
Batavia,  Leroy,  Syracuse,  Riverhead,  Oswego,  Center,  Glendale, 
Richmond  Hill,  Peniield,  Elmira,  Geneva,  Ithaca,  and  about  Brooklyn, 
N.  Y.  It  was  also  stated  to  occur  in  the  Niagara  district  in  Canada  as 
far  back  as  Hamilton,  Ontario. 

An  interesting  point  in  regard  to  the  occurrence  of  asparagus  beetles 
in  the  Niagara  peninsula  was  that  the  two  species  appeared  to  have 
arrived  almost  simultaneously  in  that  region,  but  that  the  twelve- 
spotted  form  was  by  far  the  more  common  one.  In  after  years  dif- 
ferent observers  noted  its  further  spread  in  Canada,  commenting  upon 
the  fact  that  it  led  the  common  species  in  becoming  diffused  by  natural 
means.  By  1902  it  had  appeared  in  Connecticut,  at  New  Haven,  and 
later  in  other  parts  of  that  State. 

Since  some  writers  on  these  asparagus  beetles  have  overlooked  the 
author’s  second  article* 6  it  may  be  well  to  mention  that  facts  additional 
to  those  printed  in  the  writer’s  original  article  are  given  therein, 
including  a description  and  illustration  of  the  egg  and  its  manner  of 
deposition,  and  what  is  practically  a complete  account  of  the  life  his- 
tory of  the  species,  the  insect  being  found  to  develop  and  to  feed  where 
possible  almost  exclusively  on  the  berry,  although  the  beetles  attack 
young  asparagus  shoots  before  the  berries  appear. 

« Yearbook  U.  S.  Dept.  Agric:  f.  1896  (1897),  pp.  350-351. 

&Bul.  10,  Div.  Ent.,  U.  8.  Dept.  Agric.,  pp.  57-59, 1898. 


10 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


The  young  larva. — The  freshly  hatched  larva  has  not  hitherto  been 
described.  It  may  be  briefly  described  as  follows: 

Head  rounded,  nearly  twice  as  wide  as  long  as  seen  from  above;  thoracic  plates 
distinctly  separated  at  the  middle,  with  the  intervening  space  yellow;  legs  infuscated, 
clear  whitish  at  sutures.  General  color  very  pale  yellowish,  nearly  white,  and  the 
surface  much  wrinkled.  Length  1mm.,  width  0.35  mm. 

o 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY—  BULLETIN  No.  66,  Part  II. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  WATER-CRESS  SOW  RUG. 


THE  WATER-CRESS  LEAF-BEETLE. 


F.  H.  CHITTENDEN, 

Entomologist  in  Charge  of  Breeding  Experiments. 


Issued  April  23,  1907. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE 

1907. 


CONT  F,NTS. 


Page 

The  water-cress  sowbug  ( Mancasellus  brachyurus  Harger) 11 

Descriptive 11 

Reports  of  injurious  occurrence 12 

Methods  of  control 12 

The  water-cress  leaf-beetle  ( Phcedon  aeruginosa  Suffr.) 16 

Injurious  occurrence 16 

Descriptive 16 

Literature 18 

.Habits  of  this  and  a related  species 18 

Methods  of  control 19 


ILLUSTRATIONS. 


Page. 

Fig.  3.  The  water-cress  sowbug  ( Mancasellus  brachyurus ) 12 

4.  Cross  section  of  cress  pond  showing  arrangement  for  avoiding 

damage  by  water-cress  sowbug 13 

5.  The  water-cress  leaf-beetle  ( Phcedon  aeruginosa)  : larva,  pupa, 

adult 17 


in 


I 


. 


. 


. 


Issued  April  23,  1907. 


*9 


U.  S.  D.  A.,  B.  E.  Bui.  66,  Part  II. 

SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  WATER-CRESS  SOWBUG. 

$ (Mancasellus  brachyurus  Harger. ) 

During  the  past  three  years  this  isopod  has  attracted  very  consid- 
erable attention  because  of  its  occurrence  in  troublesome  numbers  in 
water  cress  ( Nasturtium  officinale)  grown  for  market  in  portions  of 
Virginia,  West  Virginia,  and  Pennsylvania.  The  species  is  purely 
aquatic,  thus  differing  from  our  common  dooryard  sowbugs,  which, 
although  most  abundant  in  moist  locations,  are  strictly  terrestrial.  It 
belongs  to  an  entirely  different  family,  the  Asellidse,  which  contains 
three  genera,  mostly  fresh- water  forms,  inhabitants  of  streams,  wells, 
pools,  and  lakes. 

DESCRIPTIVE. 

This  species  is  so  distinct  from  the  more  common  sowbugs  (Onis- 
cidse)  that  a brief  description  will  suffice.  Its  general  appearance 
is  shown,  dorsal  view,  in  figure  3.  The  body  is  much  depressed,  and 
the  legs  are  long  and  strong.  Seen  from  the  side,  it  is  decidedly 
shrimplike.  The  peculiar  structure  of  the  antennae  may  be  noticed 
in  the  illustration.  They  terminate  in  long  flagella,  composed  of 
many  joints.  When  mature  this  sotvbug  attains  a length  of  13  or  14 
millimeters,  or  a little  upward  of  half  an  inch,  and  is  a little  more 
than  twice  as  long  as  wide,  and  gray  in  color.  This  creature  is  not  an 
insect,  but  a crustacean,  and  therefore  classed  with  crayfish  and  crabs. 
A detailed  description  is  given  by  Miss  Richardson, a who  briefly  men- 
tions McKees  Spring,  Gaylord,  and  Lexington,  Va.,  as  localities 
where  this  sowbug  was  “ reported  injurious  to  water  cress.” 

By  recent  correspondence  we  have  obtained  necessary  information 
in  regard  to  the  habits  and  manner  of  operation  of  this  sowbug,  and 
we  have  also  been  successful  in  ascertaining  what  promises  to  be  a 
very  perfect  remedy  for  the  pest  in  its  occurrence  in  streams  and  in 
spring  water.  It  appears  to  affect  cress  only  below  the  surface  of  the 
water,  attacking  the  roots  and  lower  leaves,  and  cutting  off  the  stems 

« Monograph  of  the  Isopods  of  North  America.  By  Harriet  Richardson.  Bui. 
54,  U.  S.  National  Museum,  Washington,  1905,  pp.  411-412,  figs.  400-461. 

11 


12 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


near  the  bottom,  causing  bunches  of  the  plant  to  float.  In  portions 
of  streams  where  these  sowbugs  have  been  found  most  abundantly 
they  are  frequently  seen  crawling  m a thick  mass  at  the  bottom. 
They  feed,  so  far  as  known,  exclusively  on  cress,  not  being  reported 
as  attacking  any  other  form  of  vegetation. 

REPORTS  OF  INJURIOUS  OCCURRENCES. 


This  sowbug  has  been  observed  as  a pest  since  1902.  Our  first 
report  of  its  pernicious  habits  was  made  in  1901,  when  Ave  received 
specimens  through  Mr.  J.  W.  Bryan,  Anacostia,  D.  C.,  from  Hall- 
town,  W.  Va.,  where  it  was  very  injurious  to  wateS  cress. 

In  March,  1905,  Mr.  Powell  Arnette  reported  injury  at  Gaylord, 

Va.,  to  cress  grown  in  spring  water.  The 
sow bu|>'s  were  always  found  in  the  water 
and  did  not  attack  cress  above  the  surface. 
After  destroying  the  last  vestige  of  cress 
in  one  of  his  ponds  they  remained  on  the 
bottom  “ a foot  deep,”  crawling  about  on 
the  mud. 

During  1906  (June  18)  Mr.  John  IT. 
Reed,  Carlisle,  Pa.,  wrote  in  regard  to  this 
species  and  its  destructive  work  on  water 
cress  in  his  locality.  Specimens  were  re- 
ceived August  11.  The  sowbug  was  ob- 
served principally  on  the  roots  and  lower 
leaves,  crawling  up  along  the  stem  and 
cutting  off  the  leaves.  August  10  Mr. 
George  C.  Jordan,  Washington,  D.  C.,  sent  specimens  from  Basic 
City,  Va.,  stating  that  this  “ water  bug  ” was  devouring  his  cress 
beds,  and,  since  a million  or  more  were  colonized  on  the  plants,  there 
would  be  no  crop  at  the  rate  they  were  reproducing.  When  the 
plants  were  lifted  the  sowbugs  were  observed  to  drop  from  them. 


Fig.  3. — The  water-cress  sowbug 
( Mancasellus  brachyurus).  En- 
larged (after  Richardson). 


METHODS  OF  CONTROL. 

Three  ways  of  controlling  this  species  are  suggested.  The  first 
and  most  important  consists  in  a method  of  growing  the  water  cress 
so  as  to  eliminate  injuries  by  the  sowbug.  The  second  falls  under 
the  head  of  direct  remedies,  and  none  of  these  has  as  yet  given  sat- 
isfactory results.  The  third  consists  in  the  use  of  fish  or  fowls  as 
destroyers.  This  last  means  of  eradicating  the  pest  has  not  yet  had 
a fair  trial. 

The  following  description  of  a successful  method  of  disposing  of 
the  cress  sowbug  has  been  placed  at  our  disposal  by  Messrs.  B.  Bryan 


THE  WATER-CRESS  SOWBUG. 


13 


& Son,  who  are  practical  cress  growers  and.  have  had  several  years’ 
experience  with  the  pest : 

A METHOD  OF  GROWING  WATER  CRESS  TO  DISPOSE  OF  THE  SOWBUG. 

The  damage  done  by  the  sowbug  to  water  cress  has  made  it  our  greatest 
enemy  in  cress  growing,  and  only  after  fighting  it  for  four  years  have  we  suc- 
ceeded in  finding  a way  to  keep  down  its  numbers  so  as  to  be  sure  of  a crop. 
As  cress  is  ordinarily  grown — in  lakes  or  streams  of  spring  water  anywhere 
from  6 inches  to  3 feet  in  depth — it  seems  impracticable  to  apply  any  insecti- 
cide. At  first  we  tried  to  catch  the  bugs  with  wire-netting  traps  placed  where 
the  whole  stream  of  water  had  to  pass  through  them,  but  the  bugs  remained 
among  the  cress,  and  we  caught  only  about  20  per  cent. 

Later,  in  using  copper  sulphate  to  kill  moss  in  the  cress,  we  found  that  it 
also  killed  the  sowbugs,  snails,  etc.,  when  applied  freely.  Further  experiments, 
however,  proved  that  bluestone  could  not  be  applied  in  deep  running  water  any 
better  than  the  insecticides  previously  tried,  and  when  applied  in  shallow  or 
still  water  it  injured  the  cress. 

The  method  we  are  employing  at  present  to  fight  the  sowbug  is  largely  a 
matter  of  arrangement  of  cress  beds  (see  fig.  4),  and  can  be  used  only  where 
the  bottoms  of  the  beds  can  be  graded  and  drained  or  where  level  land  adjoins 


the  source  of  the  water  supply.  We  dug  long  trenches  in  level  land,  making 
them  16  feet  wide  and  about  15  inches  deep.  Lengthwise  they  were  graded  to 
give  a fall  of  3 inches  in  100  feet,  and  crosswise  to  make  the  center  of  the 
trench  several  inches  deeper  than  the  sides.  In  the  center  and  running  the  full 
length  of  the  trench  a trough  made  of  three  10-incli  boards  was  sunk  below  the 
bottom  of  the  trench  in  such  a way  that  all  of  the  water  might  be  drained  out 
of  the  trench  through  it.  Then,  with  the  upper  and  lower  ends  of  the  trench 
and  trough  arranged  to  be  opened  or  closed,  the  trench  could  be  filled  or  emptied 
at  will  and  the  flow  of  water  regulated  up  to  8 inches  in  depth  over  the  cress. 
Of  course  fertile  soil  was  put  in  the  trenches  and  the  cress  could  be  planted 
either  before  or  after  the  water  was  turned  in. 

With  cress  beds  arranged  as  above,  manipulation  to  dispose  of  the  sowbugs 
is  simple.  By  cutting  off  the  water  supply  and  allowing  the  water  to  pass  out 
at  the  lower  end  of  the  trench,  the  sowbugs  will  collect  in  the  trough,  following 
the  receding  water,  as  they  can  live  only  in  water.  No  little  puddles  should 
remain  among  the  cress,  as  the  bugs  will  collect  in  them  instead  of  in  the  trough. 
It  will  be  found  necessary,  also,  to  use  boards  to  walk  on  in  gathering  the  cress, 
as  prints  of  one’s  boots  in  the  beds  would  make  holes  for  the  bugs  to  shelter  in. 
The  bugs  do  not  move  until  nearly  all  of  the  water  is  drawn  out  of  the  trench. 
Thus  they  are  collected  in  a small  amount  of  water  in  the  trough  and  can  then 
be  readily  killed  with  a liberal  amount  of  bluestone,  either  solid  or  in  solution. 


i 


14 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


To  make  the  work  thorough,  water  should  not  be  turned  into  the  trench  again 
for  twelve  or  twenty-four  hours,  in  which  time  the  few  bugs  left  among  the 
cress  stems  will  die  or  find  their  way  to  the  trough.  The  trenches  can  be  cleared 
of  bugs  in  warm  weather  as  frequently  as  desired,  but  less  danger  is  done  the 
cress  crop  if  the  work  is  done  just  after  gathering  the  cress. 

The  same  method  of  disposing  of  the  sowbugs  could  be  used  in  greenhouses 
in  the  winter,  but  cress  grown  in  the  open  air  could  not  be  exposed  in  freezing 
weather,  making  the  remedy  inapplicable  in  cold  weather. 

We  have  not  used  water  in  these  trenches  deeper  than  10  inches,  and  are  not 
able  to  say  how  a larger  or  more  rapidly  flowing  supply  of  water  would  act, 
nor  have  we  grown  winter  cress  in  them,  as  our  water  supply  is  insufficient 
for  that  purpose. 

OTHER  REMEDIES. 

About  the  only  other  remedies  which  we  have  been  able  to  suggest 
are  the  use  of  a substance,  such  as  sulphate  of  copper  or  chlorid  of 
lime,  which  might  be  placed  in  the  water  to  destroy  the  pest.  As 
the  former  has  already  been  tested  by  Messrs.  B.  Bryan  & Son  (see 
page  13),  it  need  not  be  mentioned  further. 

Mr.  John  H.  Reed  states  that  a grower  at  Healing  Springs,  Va., 
has  a remedy  consisting  of  a poisonous  material  which  is  placed  in 
the  water,  but  he  does  not  know  the  ingredients  nor  whether  there 
would  be  danger  to  stock  drinking  the  water  below  the  spring.  He 
writes  also  of  the  possible  use  of  chlorid  of  lime.  A tank  of  bleach 
composed  principally  of  chlorid  of  lime  ran  into  a creek  at  Mount 
Holly  Springs,  Pa.,  killed  everything  that  was  living  in  that  stream 
for  about  half  a mile  downward,  but  did  not  poison  stock  that  drank 
the  water.  The  bleach  came  from  a paper-mill  tank  which  had 
burst.  If  chlorid  of  lime  is  tested  it  should  be  used  on  a very  small 
scale  at  first  to  note  the  effect  on  plant  life.  It  is  apt  to  be  harmful 
to  trout  and  other  fish  present. 

Mr.  Reed  also  suggested  the  employment  of  ducks  to  destroy  the 
pest,  but  this  would  necessitate  the  abandonment  of  cress  culture  for 
a season,  as  the  ducks  would  injure  the  condiment  both  by  eating  it 
and  by  fouling  the  water. 

Among  other  remedies,  we  have  recommended  draining  off  the 
water  where  possible  and  exposing  the  sowbugs  to  the  drying  effects 
of  the  sun. 

FISHES  AS  A POSSIBLE  MEANS  OF  DESTROYING  THIS  ISOPOD. 

In  response  to  inquiry,  the  following  information  was  received 
from  the  Bureau  of  Fisheries,  through  Mr.  Lawrence  O.  Murray, 
Acting  Secretary,  Department  of  Commerce  and  Labor,  in  regard  to 
the  fishes  which  might  be  found  useful  in  the  destruction  of  this 
aquatic  isopod  in  its  occurrence  on  water  cress: 

Among  the  fishes  which  would  probably  prove  most  useful  for  this  purpose 
and  with  which  it  is  suggested  that  the  Department  may  wish  to  experiment 


THE  WATER-CRESS  SOWBUG. 


15 


are  the  fresh-water  killifislies  Fundulus  notatus,  F.  diaplianus,  and  F.  dispar. 
The  first  occurs  from  Michigan  to  Alabama,  Mississippi,  and  Texas,  and  is 
rather  common  in  small  lowland  ponds.  The  second  is  found  from  Maine  to 
North  Carolina  in  river  mouths,  in  the  Great  Lakes,  and  in  practically  all  of 
the  small  lakes  in  the  upper  Mississippi  Valley.  The  third  occurs  in  smaller 
lakes  and  ponds  from  northern  Ohio  to  Illinois  and  south  to  Mississippi. 
Specimens  of  each  of  these  species  could  be  obtained  at  any  one  of  several 
small  lakes  in  the  northern  part  of  Indiana. 

It  is  probable  that  some  of  the  catfishes  might  also  be  useful  in  this  connec- 
tion, and  it  is  suggested  that  it  might  be  worth  while  to  try  one  or  more  of 
the  small  species  known  as  “ mad  Toms,”  belonging  to  the  genus  Schilbeodes. 
One  or  more  species  of  this  genus  can  be  found  in  almost  any  small,  sluggish 
stream  in  Pennsylvania.  Virginia,  and  West  Virginia. 

The  writer  believes  that  carp  should  prove  of  value  in  keeping- 
down  this  cress  sowbug,  there  being  one  drawback,  however,  that  the 
carp  must  be  watched  to  see  that  they  do  not  develop  too  rapidly 
and  that  they  do  not  attack  the  cress  or  make  the  water  muddy.  Cat- 
fish have  been  tried  and  found  wanting  in  the  case  of  the  water-cress 
leaf-beetle,  which  will  be  considered  elsewhere  (pp.  16-20). 


THE  WATER-CRESS  LEAF-BEETLE. 

( Ptiasdon  ceruginosa  Suffr.) 

INJURIOUS  OCCURRENCE. 

Among  plant- feeding  native  insects  which  have  recently  appeared 
in  new  roles  is  a little  blackish  leaf-beetle,  Plicedon  ceruginosa  Suffr., 
which  was  reported  for  the  first  time  as  injurious  to  water  cress 
{Nasturtium  ojjicmale)  in  Pennsylvania,  in  1903. 

During  September  Mrs.  Hannah  B.  Hannum,  Brandywine  Summit, 
Pa.,  sent  larva?  and  adults  of  this  species,  with  statement  that  they 
were  devastating  her  water-cress  pond.  Both  larvae  and  beetles  fed 
chiefly  on  the  lower  side  of  the  leaves.  In  confinement  they  con- 
tinued feeding,  attacking  the  stalks  also.  The  larvae  all  reached 
development  about  the  same  time,  being  fully  matured  September  11 
and  12,  on  the  last  of  these  two  days  crawling  about  the  rearing  jar 
and  ceasing  to  feed.  The  pupal  period  was  not  observed,  but  it 
probably  lasted  ten  days  or  a fortnight,  as  the  weather  was  cool. 
The  beetles  continued  for  some  time  in  our  rearing  cages, -frequently 
pairing,  but  depositing  no  eggs. 

August  19,  190-1,  Mrs.  Hannum  sent  additional  specimens  of  this 
species  in  the  beetle  and  nearly  grown  larval  stages.  It  was  noticed 
that  the  beetles  did  not  swim  rapidly,  but  steadily,  and  they  were 
seemingly  not  discomposed  by  being  somewhat  out  of  their  natural 
element.  It  seems  probable  that  they  fly  from  plant  to  plant,  and 
like  most  beetles  undoubtedly  are  able  to  float  for  many  hours,  and 
perhaps  even  swim  short  distances  until  they  reach  a landing  place. 
September  13  our  correspondent  sent  still  another  lot  of  this  species, 
mostly  beetles,  but  a number  of  larvae  were  included. 

Specimens  of  the  larvae  of  a syrphus  fly  accompanied  this  sending 
and  probably  fed  at  times  on  the  small  larvae  of  the  beetle. 

DESCRIPTIVE. 

The  beetle. — This  species  belongs  to  the  tribe  Chrysomelini  of  the  ■ 
family  Chrvsomelidae.  It  is  classified  in  our  publications  on  the  j 
Coleoptera  of  America  north  of  Mexico  with  Plagiodera,  but  Eu-  I 
ropean  systematists  place  allied  forms  in  the  genus  Phaedon  Latr.,  j 
which  now  comprises  seven  species  occurring  in  our  country.  They  j 
are  very  small  semiglobose  forms.  The  outline  is  oval,  with  the  thorax 

1C, 


THE  WATER-CRESS  LEAF-BEETLE. 


17 


narrowed  anteriorly  and  the  apex  margined.  The  elytra  have  eight 
punctate  striae,  with  a short  subsutural  and  submarginal  row  of 
punctures.  The  third  joint  of  the  tarsi  is  emarginate  apically. 

The  present  species  measures  a scant  one-eighth  of  an  inch  in 
length  (3  mm.) , is  shining  bronzy  black,  and  has  the  elytral  intervals 
apparently  smooth,  but  in  reality  faintly  rugulose  when  highly  mag- 
nified, while  the  thorax  is  microscopically  reticulate.  The  original 
description  appeared  in  1858.a 

The  egg . — The  eggs  have  not  come  under  observation.  They  prob- 
ably resemble  those  of  the  European  Ph.  armor  ados  L.,  described  by 
Fryer  as  “ elongated  oval  and  of  a dark  orange  color.” 


Fig.  5. — The  water-cress  leaf-beetle  (Phcedon  ceruginosa)  : a,  adult;  b,  larva,  from  above; 
o,  same,  from  side;  d,  pupa.  Enlarged  twelve  times  (original). 

The  larva. — The  larva  appears  somewhat  like  that  of  a related 
genus,  Galerucella,  only  that  it  is  very  much  smaller.  It  is  about 
three  or  four  times  as  long  as  wide,  depending  upon  whether  it 
is  somewhat  contracted  or  fully  extended.  The  head  is  subtruncate 
in  front,  with  the  antennae  lateral  (in  preserved  specimens).  The 
head  is  shining  black,  and  the  remainder  of  the  body  very  dark  brown 
or  brownish  black  relieved  by  lighter  areas  between  the  segments. 
The  first  thoracic  segment  is  a little  wider  than  the  head ; the  sec- 
ond considerably  wider  than  that,  and  the  third  widest,  being  nearly 
as  wide  as  the  first  two  abdominal  segments.  The  second  abdominal 
is  widest,  and  at  the  same  time  the  widest  part  of  the  body.  The 
surface  is  sparsely  covered  with  long  hairs  placed  on  piliferous  tu- 
bercles, which  are  arranged  some  distance  apart,  as  shown  in  figure 
5,  h.  The  tubercles  on  the  sides  of  the  dorsum  are  sometimes  very 
prominent,  and  the  larva  is  able  to  extend  these,  possibly,  at  will. 
From  the  abdominal  segments  large  tubercular  sections  bearing  hairs 
at  their  summit  extend  on  each  side.  The  anal  segment  is  pale,  like 
the  ventral  surface,  which  bears  dark  piliferous  tubercles.  Length, 
5 mm. ; width,  1.2-1. 5 mm. 


a Ent.  Zeitung,  Stettin,  Yol.  xix,  pp.  395,  396,  1858. 


18 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


The  pupa. — The  *pupa  is  illustrated  by  figure  5,  d , which  will 
answer  better  than  a verbal  description.  The  color  is  yellow,  and  the 
length  is  slightly  less  than  that  of  the  adult. 

The  distribution  of  this  species  is  probably  moderately  wide  and 
additional  study  must  be  given  this  subject.  At  present  we  know  of 
its  occurrence  in  the  District  of  Columbia,  in  Massachusetts,  and 
probably  in  West  Virginia. 


LITERATURE. 

Brief  mention  of  the  occurrence  of  this  leaf-beetle  as  an  enemy  of 
water  cress  in  Pennsylvania  in  1893  was  made  by  the  writer,®  but 
Mr.  Frederick  Knab,  of  this  office,  mentioning  the  same  species  as 
Plagiodera  viridis , has  recorded  b its  occurrence  in  great  abundance 
upon  water  cress  near  Springfield,  Mass.,  in  1902.  The  identity  of 
the  species  in  question  has  been  verified  by  the  comparison  of  speci- 
mens, and  Mr.  Knab’s  record  was  evidently  made  on  the  assumption 
of  Crotch  c that  aeruginosa  was  merely  a variety  of  viridis. 

HABITS  OF  THIS  AND  A RELATED  SPECIES. 

We  can  not  at  the  present  writing  give  an  approximate  statement 
of  the  life  history  of  Phcedon  aeruginosa , and  hence  must  depend  on 
what  is  known  of  the  related  Ph.  armor acice,  which  is  common  to  both 
continents/  This  letter  has  evidently  been  introduced  into  this 
country,  but  its  habits  have  apparently  not  been  studied  here.  It  is 
known  in  England  as  the  blue  beetle  and  mustard  beetle/  and  is  of 
considerable  importance  locally,  in  some  seasons  ravaging  entire 
fields  of  mustard,  cress,  cabbage,  and  kohlrabi.  It  passes  the  winter 
as  adult,  reappearing  in  spring  on  cruciferous  plants.  F^er  stated 
that  in  the  three  years  prior  to  1881  the  Isle  of  Ely,  England,  suffered 
from  the  ravages  of  this  species,  entire  fields  being  injured.  Mustard 
was  attacked  at  about  the  time  of  the  formation  of  the  seed  pod  and 
after  the  stalks  were  stripped  nearly  to  the  cuticle  the  beetles  trans- 
ferred their  attention  to  kohlrabi,  which  they  completely  consumed, 
at  first  attacking  the  leaves  and  afterwards  the  bulbs,  leaving  nothing 
but  bare  stalks. 

The  water-cress  leaf-beetle  is  doubtless  no  exception  to  the  general 
rule  among  most  Chrysomelidae  and  other  species  of  Phsedon,  in 
laying  its  eggs  on  the  under  side  of  the  leaves.  Both  larvae  and 

a Ybk.  U.  S.  Dept.  Agric.  f.  1903  (1904*),  p.  504;  6 Entomological  News,  March, 
1903,  p.  89 ; c Crotch,  Proc.  Acad.  Phila.,  1873,  pp.  54,  55 ; d Pluedon  armoracice 
L.  syn. : Plagiodera  cochlcariw  Panz.,  Gyll. ; Phcedon  bctulce  Kiist.  It  is  not 
the  same  as  cochlearur  Fab.  s Fryer  and  others  have  given  accounts  of  this 
species  in  The  Entomologist  (Vol.  XIV,  pp.  44,  187,  etc.). 


THE  WATER-CRESS  LEAF-BEETLE. 


19 


adults  attack  the  cuticle  of  the  stem  after  feeding  on  the  leaves,  as 
has  been  noticed  in  the  case  of  armoracice.  E.  A.  Fitch  has  ob- 
served the  partiality  of  the  latter  for  water  cress  and  other  crucif- 
Brs  which  grow  in  watery  places  and  mentions  the  destruction  of  an 
entire  crop  of  horseradish. 

Kaltenbach  a records,  according  to  Gyllenhall  and  his  own  obser- 
vations, Veronica  beccabunga , Cardamine  amara , and  Cochlearia 
'irmoracia  or  horseradish  as  food  plants,  and  states  that  the  larva 
undergoes  metamorphosis  in  the  earth,  the  pupa  state  lasting  four- 
teen days.  Cornelius  b is  cited  as  having  observed  two  generations, 
the  spring  generation  being  found  in  May  and  June  and  the  second  in 
September.  Thomas  H.  Hart  records  the  water  starwort  of  England 
( Callitricha  verna)  as  another  host  plant.  T.  R.  Billups,0  an  ento- 
mologist as  well  as  truck  grower,  mentioning  this  species  as  Phcedon 
hetulce , states  that  it  is  “ one  of  the  greatest  insect  pests  the  market 
gardeners  around  London  have  to  contend  with.”'  Our  American 
species  undoubtedly  hibernate  as  adults  and  appear  in  early  spring 
under  boards  and  similar  shelter. 

METHODS  OF  CONTROL. 

How  to  successfully  control  this  insect  under  ordinary  conditions 
is  quite  a problem.  Paris  green  was  tried  by  our  correspondent, 
mixed  with  flour  and  sprinkled  over  the  plants  when  the  dew  was  on, 
and  this  reduced  the  numbers  of  the  insect  somewhat.  Owing  to  the 
moist  condition  of  the  plants,  however,  the  flour  formed  a paste 
which  stuck  like  glue,  and  it  was  therefore  abandoned.  Applied  in 
water  it  rolled  off  the  plants.  We  were  not  informed  if  this  appli- 
cation was  made  with  a spraying  machine.  If  the  plants  were 
sprayed  lightly  with  a fine  spray,  it  might  answer,  or,  better,  Paris 
green  dry  with  only  20  parts  of  flour,  or  plaster  or  air-slaked  lime. 
An  arsenical  should  not  be  used  within  about  a week  of  the  time  of 
cutting  the  cress  for  market.  In  the  case  of  Paris  green  there  is 
practically  no  danger  of  poisoning  even  if  it  were  used  later,  as  the 
washing  which  is  given  the  cress  will  carry  away  all  perceptible 
traces  of  the  poison. 

If  conditions  should  be  such  that  the  pond  or  stream  in  which 
water  cress  infested  by  this  species  is  growing  could  be  completely 
overflowed,  it  would  cause  the  insects  to  rise  to  the  surface,  and  in  the 
case  of  running  water  would  wash  them  downstream.  . Flooding 
alone  might  not  entirely  solve  the  problem,  as  these  beetles  are  able  to 
survive  considerable  immersion. 

When  the  cress  is  grown  in  sufficiently  large  bodies  of  water  ex- 

« Pflanzenfeinde,  p.  26;  & Stett.  Ent.  Zeit.,  1863,  p.  123;  c The  Entomologist, 
Vol.  XIV,  1881,  p.  236. 


20 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


periments  should  be  made  with  some  of  the  fish  mentioned  on  page  15 
as  possibly  useful  for  destroying  cress  insects.  Ducks  might  also  be 
found  valuable.  Catfish  were  tried,  but  without  avail. 

Mrs.  Hannum  has  recently  written  that  she  attained  the  greatest 
success  by  growing  the  water  cress  in  running  water  which  carried 
the  beetles  away.  In  cold  weather  it  was  necessary  to  plant  in 
houses  where  the  cress  did  well  until  the  coming  of  warm  and  dry 
weather,  when  the  beetles  would  sometimes  clean  it  out  almost  en- 
tirely, leaving  only  the  roots.  By  tearing  the  cress  out  of  the  houses 
and  in  ponds  which  were  not  exposed  to  running  water  she  could 
replant  her  beds,  and  hoped  in  time  to  get  rid  of  the  pest. 


O 


• 

. 

.. 

U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY- BULLETIN  No.  66,  Part  III. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  CRANBERRY  SPANWORM. 


THE  STRIPED  GARDEN  CATERPILLAR. 


F.  H.  CHITTENDEN, 

Entomologist  in  Charge  of  Breeding  Experiments. 


Issued  August  31,  1907. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE 

1907. 


CONTENTS. 


The  cranberry  spanworm  ( Cleora  pampinaria  Guen.) 

Descriptive 

Distribution 

Biologic  literature 

Unpublished  office  notes 

List  of  food  plants 

The  insect’s  life  history 

Natural  enemies  

Remedies — 

Bibliography  

The  striped  garden  caterpillar  ( Mamestra  legitima  Grote) 

Descriptive . 

Biologic  notes 

Natural  enemies  

Summary  of  habits 

Methods  of  control 


Page. 

21 

21 

23 

24 

25 

25 

26 
26 
26 

27 

28 
28 
29 

31 

32 
32 


ILLUSTRATIONS. 


Page. 


Fig.  6.  The  cranberry  spanworm  (Cleora  pampinaria ) : Moth,  larva,  and 

pupa 22 

7.  The  striped  garden  caterpillar  (Mamestra  legitima)  : Moth,  larva, 

and  pupa  29 


hi 


U.  S.  D.  A.,  B.  E.  Bui.  66,  Part  III. 


Issued  August  31,  1907. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  CRANBERRY  SPANWORM. 

( Cleora  pampinaria  Guen.) 

A brownish  spanworm  has  been  observed  by  the  writer  during 
recent  years  on  asparagus  in  the  District  of  Columbia  in  such  numbers 
as  to  indicate  that  it  is  especially  attached  to  this  crop,  at  least  in 
this  region.  In  consideration  of  the  fact  that  so  few  insects  attack 
asparagus,  the  accompanying  account  has  been  prepared.  The  spe- 
cies appears  to  have  attracted  no  attention  since  1884, 7 ° when  it 
was  considered  in  relation  to  its  appearance  in  cranberry  bogs. 
From  material  recently  collected,  several  facts  hitherto  unrecorded 
have  been  gained,  and  there  are  a number  of  unpublished  notes  of 
the  Bureau  showing  a tendency  on  the  part  of  the  species  to  become 
omnivorous.  At  any  rate  it  is  not  confined  to  cranberry,  as  the 
name  given  above  would  imply,  nor  to  strawberry,  as  might  be  in- 
ferred from  another  name,  u brown . strawberry  spanworm,”  which 
has  also  been  given  it.  The  list  of  food  plants  which  will  pres- 
ently be  furnished  shows  a considerable  range.  Owing  to  the  fact 
that  the  insect  has  not  often  been  observed  concentrated  on  any  single 
crop,  little  mention  of  it  has  been  made  in  literature  by  economic 
writers.  Cranberry  is  a favorite  food  plant,  and  is  sometimes  in- 
jured to  a considerable  extent,  especially  in  Massachusetts. 

DESCRIPTIVE. 

This  insect  belongs  to  the  lepidopterous  family  Geometridse,  the 
larvae  of  which  are  well  known  under  the  common  names  of  span- 
worms,  measuring-worms,  inch-worms,  and  loopers. 

The  moth  which  produces  this  spanworm  is  quite  variable  in  color 
and  markings.  The  average  expanse  of  wing  is  from  a little  less  than 
an  inch  to  upward  of  an  inch  and  a fourth  (22-32mm),  but  may 
exceed  this,  attaining,  according  to  Dr.  A.  S.  Packard,4  a measurement 
of  an  inch  and  a half.  The  ground  color  of  living  specimens  is  pale 

a The  numbers  in  superior  type  refer  to  corresponding  numbers  in  the 
' appended  bibliography,  p.  27. 


21 


22 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


leaden  gray,  and  of  old  mounted  material  a duller  gray,  thickly  dif- 
fused with  black  and  brown  dots  and  other  markings  more  or  less  con- 
stant, forming  irregular  lines  across  both  fore-wings  and  hind-wings. 
On  both  there  is  a marginal  regular  scalloped  black  line  and  within 
this  a strongly  dentate  or  zigzag  white  line.  The  general  pattern  of 
the  wings  varies  considerably  from  that-  shown  in  figure  6,  a , which 
represents  the  female.  The  color  of  the  body  is  similar  to  that  of  the 
wings.  The  first  abdominal  segment  is  white  above. 

The  sexes  can  be  readily  distinguished  by  the  antennae.  Those  of 
the  female  are  filiform  and  tessellated  and  those  of  the  male  rather 
strongly  pectinate,  or  feathered.  The  structure  of  the  latter  is  shown 
at  e and  /,  figure  6. 

“ It  may  be  known,”  says  Packard,  “ by  the  very  distinct  line  at  the 

base  of  the  abdo- 
¥ hJS  men,  the  basal 

wing  beyond  be- 
ing  usually 
white,  and  the 
underside  of  the 
wings  having  a 
broad  marginal 
shade,  while  the 
third  line  on  the 
fore  - wing  is 
deeply  but  quite 
regularly  sinuate 
and  near  the 
costa  acutely 
dentate.” 

A number  of 
synonyms  are 
credited  to  Cle- 
ora 'pam'pinaria.  It  has  indeed  received  five  specific  names.  As  three 
of  these  were  given  by  Guenee,  it  is  of  itself  indicative  of  the  varia- 
tion of  the  moth.  The  list  follows : 

Boarmia  sublunaria  Gn.,  Spec.  & Gen.,  IX,  248  (1857)  ; B.  frugallaria  Gn., 
Spec.  & Gen.,  IX,  240  (1857)  ; B.  collecta  Wlk.,  Cat.  Brit.  Mus.,  XXI,  p.  397 
(1800)  ; Cleora  tinctaria  Wlk.,  Cat.  Brit.  Mus.,  XXI,  p.  480  (1800)  ; Boarmia 
fraud ulentaria  Zeller,  Verb,  zool.-bot.  Ges.  Wien,  XXII,  p.  492  (1872)  ; Cymato- 
phora  parnpinaria  Pack.,  Mon.  Georn.,  p.  432  (1870). 


Fig.  6.— The  cranberry  span  worm  ( Cleora  pampinarici):  a,  Female  moth; 
b,  larva,  dorsal  view;  c,  larva,  lateral  view;  d,  pupa;  e,  male  antenna; 
/,  enlarged  joints  of  same.  All  enlarged;  e,f,  more  enlarged  (original). 


The  e(j(j  appears  not  to  have  been  described. 

The  larva. — The  larva  resembles  those  of  other  geometrids  in  being 
of  elongate  form,  about  nine  times  as  long  as  wide,  with  the  three 
pairs  of  thoracic  or  front  legs  bunched  closely  together  near  the  head, 
and  in  having  only  two  pairs  of  prolegs,  or  unjointed  legs,  at  the 


THE  CRANBERRY  SPANWORM. 


23 


opposite  extremity.  The  color  varies  to  a considerable  extent  from 
mottled  pale  yellowish  to  brown,  often  with  an  olivaceous  or  greenish 
tint.  Those  which  have  been  recently  captured  in  the  District  of 
Columbia  are  reddish  brown,  mottled,  streaked,  and  lined  with  lighter 
yellowish,  red,  and  black.  The  head  is  strongly  marked  wTith  trans- 
verse irregular  black  bands.  The  thoracic  segments  are  marked 
above  by  a pair  of  thin  median  longitudinal  lines.  The  second 
abdominal  segment  bears  on  the  dorsal  surface  a pair  of  prominent, 
widely  separated,  mostly  black  tubercles,  but  in  some  individuals 
these  are  wanting.  The  penultimate  segment  also  bears  above  a 
smaller  pair  of  black  tubercles.  The  larva  when  fnll  grown  measures 
an  inch  to  upward  of  an  inch  and  a fourth  in  length  (25-33mm)  and 
the  greatest  diameter  is  about  one-eighth  of  an  inch  (3mm).  The  singu- 
lar construction  of  the  legs,  or  rather  the  lack  of  the  intermediate  legs 
usually  present  in  caterpillars  of  other  families,  is  the  cause  of  the 
peculiar  motions  of  the  spanworms  in  crawling  about  in  search  of 
food,  which  have  given  them  their  popular  names.  When  in  motion 
a larva  extends  its  body  to  full  length,  then  brings  the  posterior  legs 
close  to  the  anterior  ones,  causing  the  body  to  loop  in  the  center. 
The  body  is  then  stretched  out  again,  these  actions  being  repeated 
alternately. 

When  this  spanworm  is  in  repose  it  attaches  itself  to  the  foliage — 
for  example,  to  the  stem  of  asparagus — by  means  of  its  anal  pair  of 
legs  and  stretches  out  its  body  rigidly  and  at  an  angle  so  that  its 
natural  colors  harmonize  with  the  foliage  or  with  the  landscape. 
On  this  head  Doctor  Smith  has  remarked  that  on  a section  of  cran- 
berry bog  on  which  this  species  is  feeding  the  observer  may  stand  in 
the  midst  of  thousands  of  them  and  see  none  until  something  starts 
them  into  motion.  Then  it  appears  almost  as  though  the  entire  bog 
were  alive.  As  the  spawnworms  hang  somewhat  tenaciously  to  their 
food  plants,  they  are  undoubtedly  present  frequently  in  numbers 
without  anyone  being  the  wiser. 

The  half-grown  larva  is  described  by  Doctor  Forbes.8 

The  pupa , shown,  ventral  view,  in  figure  6 at  d , is  of  robust  form, 
light  greenish  brown  in  color,  and  a little  less  than  half  an  inch  in 
length  (12mm)  and  about  a third  of  that  (4mm)  in  width. 

DISTRIBUTION. 

The  wide  distribution  of  this  insect  is  shown  by  the  following  list 
of  localities,  based  upon  Doctor  Packard’s  list,  where  the  authorities 
for  each  locality  are  given : Maine ; Amherst,  Cape  Cod,  Cotuit, 
Xatick,  Mass.;  West  Farms,  Center,  Albany,  and  Brewster,  N.  Y. ; 
Philadelphia,  Pa.;  Lansing,  Mich.;  Dayton,  Ohio  (Pilate);  Glen- 
coe, Nebr. ; Cadet,  Mo.;  Centralia  and  elsewhere  in  Illinois;  Wash- 
ington and  Brookland,  D.  C. ; Georgia;  Calhoun,  Dawson,  and  De- 


24 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


mopolis,  Ala. ; Lake  Bearsford,  Florida ; Bastrop  County  and  else- 
where in  Texas. 

The  above  localities  indicate  a distribution  ranging  from  the 
transition  life  zone  through  the  upper  to  the  lower  austral.  The 
occurrence  of  the  species  in  Florida,  Alabama,  and  Texas  would 
indicate  that  it  is  to  be  found  throughout  the  Gulf  region.  The 
insects  observed  by  Glover  were  stated  to  ajipear  in  the  Carolinas, 
Georgia,  and  Florida  in  early  October. 

BIOLOGIC  LITERATURE. 

The  spanworm  under  consideration  was  described  under  the  name 
cf  Boarmia  pampinaria  by  Guenee  in  1857.2  In  1876  Dr.  A.  S. 
Packard  gave  a detailed  description  of  the  moth,  with  a consideration 
of  its  distribution  and  remarks  on  the  larva  and  pupa,  the  former 
being  stated  to  feed  on  pear.10  In  1881  Dr.  G.  H.  French6  had  a 
note  on  the  larva  observed  feeding  on  willow  and  geranium;  larvse 
transformed  to  pupse  September  16  and  October  2,  and  the  imagoes 
issued  April  17  of  the  following  year.  During  the  year  1883  this 
species  was  observed  by  Dr.  J.  B.  Smith,7  then  a temporary  agent 
of  this  office,  doing  injury  at  Cotuit,  Mass.  During  that  year  the 
spanworms  were  so  abundant  in  the  cranberry  bogs  in  that  vicinity 
that  their  numbers  could  be  compared  only  to  the  army  worm 
(Heliophila  unipuncta  Haw.).  In  the  case  in  question  they  began  in 
a space  about  a rod  square,  devoured  that,  and  spread  in  a direct 
line  across  the  bog.  The  number  of  moths  that  would  have  been 
produced  from  these  insects  should  they  have  been  permitted  to 
transform  was  described  as  being  44  frightful.”  A rather  full  account 
by  Dr.  S.  A.  Forbes  followed  in  1884, 8 in  which  the  statement  was 
made  that  the  larva  was  found  in  midsummer  feeding  on  leaves  of 
strawberry  in  southern  Illinois.  Larvie  obtained  August  1 pupated 
on  the  11th,  and  the  moths  emerged  on  the  22d,  giving  eleven  days  as 
the  pupal  stage  at  that  season.  Larvae  collected  September  6,  about 
half  grown,  were  believed  to  represent  a second  generation.  The 
larva  of  this  species  came  under  the  observation  of  the  writer  on 
asparagus  first  in  1897.11  In  1899  Doctor  Lugger  12  stated  that  the 
caterpillars  were  found  on  apple  and  blackberry,  and  that  there  were 
at  least  two  generations  annually. 

As  this  is  one  of  the  commonest  species  of  its  genus,  of  wide  dis- 
tribution, and  authentically  determined  as  living  on.  cotton,  there 
seems  little  doubt  that  it  was  the  type  of  Glover’s  account  of  44  the 
larger  spanworm,”  figured  and  described  in  his  accounts  of  insects 
frequenting  the  cotton  plant,  published  in  1856  1 and  again  in  1878.5 
A curious  blunder  was  made  by  M.  I).  Landon,  who  figured  this 
species  as  the  44  cotton  caterpillar  ( Xoctua  xylina )”  in  1865, 3 this 
illustration  being  a crude  copy  taken  from  Glover’s  first  or  1856 
account  of  this  spanworm. 


THE  CRANBERRY  SPANWORM. 


25 


UNPUBLISHED  OFFICE  NOTES. 

June  5,  1879,  we  received  from  Mr.  William  Trelease,  then  at 
Dawson,  Ala.,  larvae  found  feeding  on  cotton.  June  12  a larva 
kept  under  observation  changed  to  pupa,  and  on  June  26  the  moth 
issued,  this  individual  having  passed  14  days  as  pupa.  The  same 
year  the  moth  was  reared  on  several  occasions  from  material  obtained 
on  red  clover  in  the  District  of  Columbia  by  Messrs.  Pergande  and 
Howard.  June  28  the  moth  issued  from  the  pupa.  August  15  the 
larva  was  observed  feeding;  changed  to  pupa  August  25,  and  issued 
as  moth  March  1 of  the  following  year.  August  29  the  larva  was 
observed  feeding;  changed  to  pupa  September  4,  the  moth  issuing 
March  22  of  the  next  year. 

February  6,  1880,  we  received  from  Lake  Bearsford,  Fla.,  from 
Prof.  J.  H.  Comstock,  a larva  obtained  on  orange. 

There  are  also  reared  specimens  of  moths  in  the  U.  S.  National 
Museum  bearing  labels  showing  the  rearing  of  moths  and  occurrence 
of  larvae  on  different  plants,  as  follows:  On  locust,  May  6,  1893, 
District  of  Columbia;  hickory,  November  24,  1894,  Cadet,  Mo.,  and 
August  4 of  the  same  year  on  pear,  locality  presumably  the  District 
of  Columbia.  There  is  also  a specimen  labeled  “ on  guava,’’  proba- 
bly from  Florida. 

August  6,  1904,  specimens  of  this  spanworm  were  received  from 
Calhoun,  Ala.,  where  they  were  found  feeding  on  cotton  and  were 
mistaken  for  the  cotton  leaf-worm  ( Alabama  argillacea  IIbn.).  The 
adult  issued  August  29.  Larvae  were  about  full-grown  when  received, 
August  9,  and  it  seems  probable  that  they  underwent  a short  stage 
of  aestivation  before  transforming  to  pupae,  as  the  pupal  stage  is  less 
than  20  days  in  midsummer. 

During  the  first  two  weeks  of  October  for  several  years  larvae  have 
been  observed  on  asparagus  grown  in  the  District  of  Columbia,  the 
species  appearing  in  moderate  numbers.  The  first  moth  that  has 
been  reared  from  October-collected  larvae  appeared  in  January,  and 
others  appeared  in  February.  As  this  was  in  confinement  the  dates 
were  not  natural  ones. 

LIST  OF  FOOD  PLANTS. 

It  is,  as  previously  remarked,  owing  to  the  omnivorous  habit  of  this 
species,  causing  a distribution  of  attack,  that  noticeable  injury  has 
not  been  ascribed  to  it  elsewhere  than  in  cranberry  bogs.  It  is  com- 
mon enough  in  the  vegetable  and  truck  garden,  but  not  confined  to 
any  particular  place  on  the  farm,  occurring  in  orchards,  on  forest 
and  shade  trees,  and  on  other  plants.  The  list  of  observed  food  plants 
includes  asparagus,  strawberry,  blackberry,  ornamental  geranium, 
apple,  pear,  orange,  willow,  hickory,  cranberry,  honey  locust,  cotton, 
clover,  and  guava.  As  a rule  the  larvae  confine  themselves  to  the 


26 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


foliage  of  these  plants,  but  Glover  states  that  they  sometimes  feed 
upon  the  petals  of  the  flowers  of  cotton,  although  doing  little  harm 
to  the  general  crop. 

THE  INSECT’S  LIFE  HISTORY. 

Our  knowledge  of  the  life  history  of  this  species  is  somewhat 
incomplete.  The  repeated  rearing  of  moths  in  early  spring  and  the 
occurrence  of  larvae  in  the  latter  part  of  June  in  Massachusetts  as 
recorded  by  Smith,  as  also  in  the  District  of  Columbia  and  elsewhere 
as  late  as  October,  noted  by  the  writer  and  others,  show  at  least  two 
generations  in  the  Northern  States,  while  the  record  of  the  occur- 
rence of  the  moths  in  March  in  Texas  (by  Belfrage)  would  indi- 
cate that  in  the  Gulf  States  there  may  be  an  additional  generation. 
It  would  seem  practically  impossible  for  larvae  hatching  from  eggs 
deposited  in  early  spring  to  require  until  late  October  to  attain 
maturity,  hence  the  natural  inference  of  two  generations  for  a 
climate  like  the  District  of  Columbia.  The  cranberry  growers  of 
Massachusetts  claim  two  generations  for  that  State,  one  appearing 
as  larvae  in  June  and  early  July,  the  other  in  the  latter  part  of 
August, 

The  eggs  are  unknown,  and  the  periods  of  egg  and  larva  have 
not  been  ascertained,  but  the  pupal  condition  has  been  observed  to 
be  passed,  for  the  first  generation,  in  from  11  to  14  days,  while  the 
over-wintering  pupa  consumes  five  or  six  months  in  the  District  of 
Columbia,  a shorter  time  farther  south,  and  a longer  time  northward. 

The  date  of  the  appearance  in  the  North  of  the  first  moths  has 
not  been  learned  positively  nor  the  natural  time  of  emergence  of  the 
first  new  generation  of  moths. 

NATURAL  ENEMIES. 

Doctor  Smith 7 has  stated  that  the  larvae  of  this  span  worm  are 
checked  by  parasites,  'but  that  in  some  localities  almost  every  year 
they  become  numerous  enough  to  be  destructive.  In  some  years, 
however,  in  the  cranberry  bogs  of  New  Jersey  they  are  not  seen  at 
all,  showing  great  scarcity,  due  probably  in  part,  at  least,  to  natural 
causes.  Only  one  parasite  for  this  species  is  known,  namely,  Ex 
orista  Jjoarmice  Coq.,  a tachina  fly  reared  at  this  Department  from 
Cotuit  and  other  localities  in  Massachusetts  several  years  ago. 

REMEDIES. 

This  species  is  not  difficult  to  control  ou  asparagus  or  other  truck 
crops.  As  it  feeds  in  free  exposure  on  the  foliage,  spraying  with 
Paris  green  or  arsenate  of  lead  will  destroy  it,  and  when  either  of 
these  insecticides  is  used  for  the  asparagus  beetles  it  will  kill  all  of 
the  spanworms  which  may  be  present.  The  Paris  green  may  be 


THE  CRANBERRY  SPANWORM. 


27 


used  at  the  rate  of  1 pound  to  about  100  to  150  gallons  of  water,  and 
the  arsenate  of  lead  at  the  rate  of  about  1 pound  to  25  to  50  gallons 
of  water.  The  same  remedies  will  apply  equally  well  to  the  occur- 
rence of  this  species  in  cranberry  bogs. 

BIBLIOGRAPHY. 

1.  Glover,  Townend.  Report  Commissioner  Patents,  p.  92,  Plate  VIII,  fig.  4, 

1855  (1856). 

Probably  Ibis  species.  Appears  in  Carolinas,  Georgia,  and  Florida  early  in 
October  and  feeds  upon  the  petals  of  the  cotton  flower  ; larva  and  adult  described 
and  figured. 

2.  Guenee,  M.  A.  Species  General  cles  Lepidopteres,  Yol.  IX,  Plialenites, 

pp.  245,  246,  248,  1857. 

Original  description  as  Boarmia  pampinaria  from  near  Baltimore,  as  B.  frugal - 
laria  from  Georgia,  and  as  B.  sublunaria  from  North  America. 

3.  Landon,  M.  D.  Rept.  Comm.  Agr.  f.  1864  (1865),  p.  90. 

Erroneously  figured  as  the  “cotton  caterpillar  ( Noctua  xylina).” 

4.  Packard,  A.  S.  Report  IT.  S.  Geological  Survey  Terr.,  Hayden,  Yol.  X, 

pp.  432,  442,  Plate  XI,  fig.  20,  1876. 

Technical  and  detailed  description  of  moth  ; synonymy  ; distribution  and  note 
on  larva  and  pupa,  the  former  feeding  on  pear. 

5.  Glover,  Townend.  Cotton  and  its  principal  injurious  insects< Washington, 

D.  C.,  Plate  VII,  figs.  6,  7,  8,  1878. 

Figures  larva,  chrysalis,  and  moth  ; found  early  in  October  in  Georgia  feeding 
on  flowers  of  the  cotton  plant. 

6.  French,  G.  H.  Papilio,  Yol.  I,  p.  82,  1881. 

Notes  on  larva  found  feeding  on  willow  and  geranium. 

7.  Smith,  J.  B.  Bui.  4 (o.  s.),  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  26-28,  1884. 

A two-page  account  in  reference  to  injuries  to  cranberries ; description  of 
larva  ; referred  to  as  Cymatophora  pampinaria ; remedies. 

8.  Forbes,  S.  A.  Thirteenth  Rept.  State  Entomologist  Illinois,  pp.  76-78,  1883 

(1884). 

A rather  full  account.  Larva  found  frequently  in  midsummer  in  southern 
Illinois  feeding  on  leaves  of  strawberry  ; description  of  larva,  pupa,  and  imago 
(quoted  from  Packard). 

9.  Forbes,  S.  A.  Trans.  Miss.  Valley  Hort.  Soc.,  Yol.  II,  p.  235,  1884. 

Quotations  of  first  two  paragraphs  of  No.  8. 

10.  Packard,  A.  S.  Fifth  Report  U.  S.  Ent.  Commission,  p.  654,  1890. 

Included  in  a list  of  insects  affecting  honey  locust  ( Gleditschia  triacanthos) . 

11.  Chittenden,  F.  FI.  Bui.  10,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  p.  61,  1898. 

An  unknown  geometrid  larva  feeding  on  asparagus  ; subsequently  ascertained 
to  be  this  species. 

12.  Lugger,  Otto.  Fourth  Rept.  Entomologist  State  Exp.  Station  Minn.,  pp. 
187,  188,  fig.  188,  1898  (1899). 

Notes  on  the  moth  ; caterpillar  found  on  the  apple  and  blackberry.  Short  gen- 
eral account. 

13.  Smith,  J.  P>.  Farmers’  Bulletin  178,  U.  S.  Dept.  Agriculture,  pp.  19-21, 
1903. 


Account  of  injuries  to  cranberry,  life  history,  and  remedial  measures. 


THE  STRIPED  GARDEN  CATERPILLAR. 

( Mamestra  legitima  Grote.) 


A strikingly  beautiful  black  and  yellow  striped  caterpillar  is  fre- 
quently found  in  gardens,  and  occasionally  in  such  numbers  as  to 
attract  attention.  It  is  a general  feeder,  like  most  of  its  kind,  but  is 
somewhat  partial  to  asparagus,  cruciferous  plants,  peas,  and  other 
leguminous  vegetables.  Its  occurrence  in  the  District  of  Columbia  in 
some  numbers,  especially  on  asparagus,  has  permitted  a study  of  the 
species,  which  adds  somewhat  to  what  has  previously  been  published. 
Only  a few  short  notices  of  this  insect  have  appeared  in  publications 
of  the  Department  of  Agriculture  or  elsewhere,  to  the  writer’s  knowl- 
edge. The  following  somewhat  brief  account  is  therefore  presented. 

This  species  is  a noctuid,  related  to  the  cutworms,  and  is  congeneric 
with  the  zebra  caterpillar  ( Mamestra  picta  Harr.).  The  moth  was 
originally  described  in  1864,®  the  species  at  that  time  being  known 
from  the  middle  and  eastern  States,  where  it  was  stated  to  be  com- 
mon. It  is  also  recorded  as  occurring  in  the  northern  States.  Evi- 
dently, considering  its  numbers  in  the  Gulf  region,  it  may  be  found 
in  most  States  east  of  the  Mississippi  River  Valley. 

DESCRIPTIVE. 

The  moth  is  quite  prettily  marked,  as  can  be  seen  by  referring  to 
figure  T>  a.  The  prevailing  tint  of  the  fore-wings  is  a light  lead 
color,  marked  with  velvety-black  and  brown  spots,  the  pattern  varying 
somewhat  but  usually  about  as  figured.  The  lower  wings  are  fawn 
colored,  with  dusky  margins,  and  the  veins  are  moderately  prominent. 
The  females,  as  is  usual  with  this  group,  have  the  abdomen  as  illus- 
trated, while  the  males  have  abdomens  with  bushy  tips.  The  wing 
expanse  is  a little  more  than  an  inch  and  a quarter. 

The  eggs . — No  description  of  the  egg  is  available  at  the  present 
writing. 

The  larva  is  also  a pretty  form  and  its  markings  recall  the  zebra 
caterpillar.  It  will  be  noticed  by  the  figure  (fig.  T,  &,  c)  that  there  is 
considerable  difference,  however,  and  the  two  species  are  not  at  all 
likely  to  be  confused  by  anyone  who  carefully  examines  them.  The 
present  species  has  a larger  and  wider  head  and  is  darker  than  is 
usual  with  the  common  zebra  caterpillar.  The  appearance  of  the 
head  from  in  front  is  shown  at  d.  The  stripes  with  which  the  body  is 

"Apamea  legitima , Proc.  Ent.  Soe.  Phila.,  Vol.  Ill,  p.  82. 

28 


THE  STRIPED  GARDEN  CATERPILLAR. 


29 


ornamented  are  black  and  yellow,  as  with  the  zebra  caterpillar,  but  the 
lateral  stripe  is  divided  into  two  portions,  the  upper  one  lighter  than 
the  lower,  and  the  entire  lateral  surface  when  marked  consists  of 
regular  stripes,  whereas  in  the  other  species  these  stripes  are  broken 

up. 

The  pupa,  when  mature,  is  nearly  black  in  color,  and  has  the 
appearance  illustrated  (fig.  7,  e).  It  measures  about  five-eighths  of 
an  inch  in  length,  including  the  tips. 

BIOLOGIC  NOTES. 

This  species  was  briefly  mentioned  as  having  been  found  by  the 
writer  in  the  larval  condition  on  asparagus  at  Marshall  Hall,  Md., 
in  October,  1896.®  At  that  time  it 
was  impossible  to  ascertain  whether 
or  not  it  bred  from  eggs  deposited 
on  this  plant,  but  later  observations 
conducted  in  company  with  Mr. 

F.  C.  Pratt  during  the  first  and  sec- 
ond weeks  of  October  show  con- 
clusively that  such  must  be  the  case, 
as  larvse  were  found  in  the  greatest 
abundance  on  three  large  patches  of 
asparagus  at  Brookland,  D.  C. 

They  usually  occurred  singly,  but 
occasionally  in  pairs. 

During  the  heat  of  the  day,  in 
the  moderately  cool  and  seasonable 
Indian  summer  weather  usual  at 
Washington  at  that  time  of  the 
year,  many  larvae  would  be  found 
stretched  out  upon  dry  sprigs  of 
asparagus,  and  in  spite  of  their 
bright  colors  they  would  easily  have 
escaped  the  observation  of  anyone  without  experience  in  insect  col- 
lecting. The  larva,  in  fact,  furnishes  a good  example  of  protective 
coloration.  An  individual  would  be  in  plain  sight,  and  then  if  one’s 
eyes  were  directed  elsewhere  for  a moment  it  would  sometimes  be 
difficult  to  find  it  again,  although  it  might  be  within  a foot  of  the 
observer. 

Larvae  obtained  October  7 and  later  were  kept  feeding  on  asparagus 
in  our  rearing  cages  until  the  third  week  of  October,  when  they  de- 
scended to  the  earth  and  soon  afterwards  assumed  the  pupal  condition. 
The  exact  date  of  the  assumption  of  the  chrysalis  form  was  not  ascen- 
ts Bui.  10,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  p.  60. 


Fig.  7. — The  striped  garden  caterpillar 
( Mamestra  legitima)  : a.  Adult ; 6, 
larva  from  above  ; c,  same  from  side  ; 
d,  head  of  same  from  front : e, 

pupa.  All  natural  size  except  d, 
which  is  enlarged  (from  Howard). 


30 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


tained,  but  it  was  about  the  21st  of  October,  which  would  give  a 
period  for  the  pupa  of  ten  months,  as  the  moths  of  this  lot  began 
issuing  August  21.a 

One  individual  transformed  to  pupa  October  17  and  the  imago 
issued  August  24  of  the  following  year. 

October  15,  1898,  the  larva  was  brought  to  the  writer  by  Mr.  P.  H. 
Dorsett,  from  his  greenhouse  at  Garrett  Park,  Md.,  where  the  species 
was  feeding  on  the  foliage  of  violet.  The  same  year,  November  3, 
this  larva  was  found  rather  abundantly  by  Doctor  Howard  in  tobacco 
fields  in  southern  Virginia,  near  the  North  Carolina  border  line,  upon 
the  leaves,  which  in  some  cases  were  badly  ragged.6  The  first  moths 
issued  in  July. 

During  1900  and  1901  correspondence  was  had  in  regard  to  this 
caterpillar  with  Mr.  IT.  Walter  McWilliams,  Griffin,  Ga.,  who  sent 
specimens,  as  also  larvae  of  the  so-called  cotton  cutworm  ( Prodenia 
ornithogalli  Guen.),  with  which  the  insect  was  associated  in  both 
years.  The  caterpillars  were  noticed  there  in  greatest  numbers  during 
November,  and  both  species  were  reported  as  destroying  a number  of 
garden  crops,  among  which  were  cabbage,  collards,  turnip,  ruta-baga, 
rape,  peas  and  related  plants,  as  also  some  other  vegetables.  Mature 
larvae  were  seen  as  late  as  the  last  week  of  November. 

Among  other  office  records  are  two  which  also  have  a bearing  on 
the  biology  of  this  species.  One  of  these  was  made  by  Mr.  Theo. 
Pergande,  who  found  the  larvae  in  the  District  of  Columbia  feeding 
on  blackberry  and  on  flowers  of  a goldenrod  ( Solidago  sp.).  The 
other  is  a short  note  by  Mr.  F.  M.  Webster  upon  the  rearing  of  the 
moth  in  spring  from  the  seed  pods  of  milkweed  ( Asclepias  incar-, 
nata ),  near  Lafayette,  Ind.  “ The  larva  appeared  to  subsist  upon  the 
seeds,  the  pods  being  attached  unopened  to  the  wrecked  plant.” c 

October  21  the  larva  was  found  at  Washington,  D.  C.  We  have  no 
further  records  in  regard  to  the  habits  of  this  species  other  than  the 
capture  of  moths  in  the  District  of  Columbia  July  25,  August  22  and 
25,  and  September  2,  and  there  are  specimens  also  in  the  U.  S. 
National  Museum  from  Lewis  County,  N.  Y.,  July  4,  collected  by 
O.  Meske,  and  others  from  New  Jersey  without  definite  locality.  The 
species  is  also  said  to  occur  at  Portland,  Oregon.  It  is  interesting  to 
note  that  among  these  specimens  are  inflated  larvae  and  mounted 
heads  labeled  u pretty  cutworm,”  which  might  be  termed  a manu- 

« The  rearing  jar  was  kept  under  somewhat  unnatural  conditions,  at  times 
too  warm  and  dry,  but  the  effect  of  one  condition  might  have  been  counteracted 
by  another,  and  the  date  of  issuance  of  the  adults  was  not  far  from  that  which 
would  be  assumed  in  nature — more  likely  earlier  than  otherwise. 

& Yearbook  U.  S.  Dept.  Agric.  for  1808,  p.  142. 

c Insect  Life,  Vol.  II,  p.  382,  1800. 


THE  STRIPED  GARDEN  CATERPILLAR. 


31 


script  name,  as  1 do  not  find  this  insect  mentioned  under  this  cogno- 
men in  print.  With  present  knowledge  of  the  species  it  can  not 
properly  be  classified  as  a cutworm. 

Among  the  files  of  the  Department  of  Agriculture  there  are  a few 
notes  which  are  of  interest  as  showing  the  cycle  of  periods  from  egg 
to  about  the  last  stage  of  the  larva.  These  notes  were  made  in  1882 
by  Mr.  Albert  Koebele,  and  the  mounts  which  were  made  with  them 
are  not  sufficiently  fresh  for  description.  From  these  notes  the  fol- 
lowing is  taken : 

Moths  collected  at  sirup,  near  the  District  of  Columbia,  Septem- 
ber 16,  were  placed  in  a rearing  jar  with  grass,  where  two  batches 
of  eggs  were  laid  between  11  and  12  o’clock  at  night,  one  of  these 
being  deposited  around  the  stem  of  grass. 

September  18  the  eggs  hatched,  showing  the  egg  period  to  be  only 
2 days.  On  the  21st  the  larvae  had  completed  the  first  molt,  making 
the  first  larval  instar  3 days.  September  23  the  second  molt  was 
observed,  which  gives  2 days  as*  the  second  larval  instar.  September 
27  lar  vse  changed  their  third  skin,  leaving  5 days  as  the  period  of 
the  third  instar. 

October  1 the  fourth  molt  occurred,  making  4 days  for  the  fourth 
instar.  By  October  9 all  the  larvae  had  changed  the  fifth  skin,  when 
they  developed  cannibalistic  tendencies  and  were  removed  to  a larger 
jar.  The  period  of  this  instar  was  8 days.  The  remaining  larvae 
refused  to  eat  and  finally  died,  so  that  the  complete  life  cycle  could 
not  be  ascertained. 


NATURAL  ENEMIES. 

Soon  after  bringing  larvae  in  from  the  field  some  were  noticed  to 
be  dying  from  fungous  attack.  In  the  asparagus  fields  Estigmene 
(Leucarctia)  acrcea  Dru,  and  Dissosteira  Carolina  L.,  the  salt-marsh 
caterpillar  and  Carolina  locust,  respectively,  were  also  dying  in  con- 
siderable numbers,  and  it  was  conjectured  that  the  disease  might  have 
originated  with  these  and  spread  to  the  Mamestras.  After  the  dis- 
eased caterpillars  had  been  frequently  removed,  however,  the  fungous 
attack  abated.  Specimens  of  infected  larvae  Avere  referred  to  the 
Bureau  of  Plant  Industry,  and  the  fungus  was  identified  by  Mrs. 
Flora  W.  Patterson,  assistant  pathologist,  as  an  undescribed  species 
of  Verticillium.  At  another  time  larvae  which  showed  signs  of  dis- 
ease after  capture  were  examined  by  Mrs.  Patterson,  who  recognized 
the  presence  of  the  fungus  Sporotrichum  minimum  Speg.  A larva, 
when  placed  with  diseased  insects,  including  some  of  its  own  species, 
did  not  contract  the  fungous  disease,  from  which  it  seems  probable 
that  the  disease  is  not  readily  communicable,  and  hence  of  no  use  as  a 
possible  means  of  destroying  this  species. 


32 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


SUMMARY  OF  HABITS. 

From  present  knowledge  of  the  caterpillar  two  generations  annually 
are  indicated,  although  only  one  has  been  observed.  Moths  have  been 
reared  by  the  writer  in  July  and  August  and  they  have  been  captured 
out  of  doors  during  the  same  months  and  in'  September.  From 
available  data  it  would  appear  that  an  average  life  history  would  be 
about  as  follows : Egg  period,  3 to  5 days ; first  larval  instar,  3 days ; 
second  larval  instar,  2 days;  third,  5 days;  fourth,  4 days;  fifth, 

8 days,  and  pupal  stage,  7 to  10  months.  Hibernation  occurs  in  the 
pupal  stage. 

The  observed  food  plants  include  asparagus,  cabbage,  collards, 
turnip,  ruta-baga,  rape,  peas  and  related  plants,  greenhouse  violet, 
tobacco,  grass,  and  blackberry.  Of  wild  plants,  golden-rod  and 
milkweed  have  been  observed,  the  larva  attacking  the  flowers  of  | 
the  former  and  the  seed,,  pods  of  the  latter. 

METHODS  OF  CONTROL. 

Although  the  early  habits  of  this  species  as  it  occurs  in  the  field 
have  not  been  observed,  there  is  no  doubt  that,  like  the  zebra  cater- 
pillar, the  young  when  first  hatched  are  gregarious  for  some  time, 
and  hence  may  be  easily  discovered  and  destroyed  by  mechanical 
means  or  by  arsenicals.  All  of  the  caterpillars  of  this  class  readily 
succumb  to  arsenical  poisons,  and  for  this  species  in  its  occurrence  on 
asparagus  and  some  other  plants  arsenate  of  lead  is  to  be  preferred. 
It  may  be  used  at  the  rate  of  about  1 pound  combined  with  15  to  25 
gallons  of  water  or  Bordeaux  mixture.  If  an  adhesive  resin  soap, 
such  as  resin  fish-oil  soap,  is  added,  it  makes  this  mixture  all  the 
more  permanent,  and  a single  application  is  then  all  that  is  necessary. 
Paris  green  may  be  used  in  the  same  manner  at  the  rate  of  1 pound 
to  100  or  150  gallons  of  water.  It  is  evident  that  this  species,  like  I 
the  zebra  caterpillar,  does  no  particular  harm  as  a rule  in  its  first  i 
generation,  but  is  much  more  abundant  in  the  second  or  late  fall  gen-  j 
eration,  when  certain  plants  are  injured  by  it.  Owing  to  the  diffi-l] 
culty  of  locating  the  larger  larvae,  it  is  evident  that  hand-picking f 
would  not  be  applicable  for  them  in  their  later  stages. 


O 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY— BULLETIN  No.  66,  Part  IV. 

L.  O:  HOWARD,  Entomologist  and  Chief  of  Bureau. 


INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


AND  THEIR  RELATION  TO  THE 
“CURLY -LEAF”  CONDITION. 


E.  D.  BALL,  Ph.  D., 


Special  Field  Agent. 


Issued  January  27,  1909. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1909. 


CONTENTS. 


Page. 

Introduction 33 

The  beet  leafhopper  ( Eutettix  tenella  Baker) 35 

Descriptive 35 

The  adult 35 

The  eggs 35 

The  nymphs  35 

Food  plants 35 

Distribution 36 

Life  history  studies 36 

Record  at  Lehi,  Utah 36 

Record  at  Monroe,  Utah 38 

Other  records  in  Utah 38 

Cage  experiments,  Lehi,  Utah 38 

Summary  of  iife  history 40 

Economic  relations 41 

Characteristics  of  1 1 curly-leaf  ”... 44 

Other  records 46 

Economic  summary  and  proposed  remedies 47 

Bibliographical  references 48 

Other  leafhoppers . - 49 

Eutettix  strobi  Fitch 49 

Eutettix  scitula  Ball 49 

Eutettix  seminuda  Say 50 

Eutettix  clarivida  Van  Duzee 50 

Eutettix  insana  Ball,  E.  albida  Ball,  and  E.  pauperculataBedl 50 

Eutettix  stricta  Ball 50 

Agallia  sanguinolenta  Prov 51 

Agallia  cinerea  Osborn  and  Ball 51 

Agallia  bigelovise  Baker 51 

Agallia  quadripunctata  Prov.  and  A.  novella  Say 51 

Empoasca  sp 51 

Conclusions  in  regard  to  “curly-leaf” 52 

66  —iv 

III 


ILLUSTRATIONS. 


PLATES. 

Plate  I.  Leafhoppers  ( Eutettix  spp.)  and  their  work.  Fig.  1. — Eur 
tettix  tenella:  a,  Adult;  b,  nymph;  c,  wing;  d,  e,  geni- 
talia; /,  eggs  (greatly  enlarged)  ; g,  section  of  beet  stem, 
showing  fresh  eggs  in  place;  h,  same,  showing  eggs  ready 
to  hatch ; i,  old  egg  scars  on  beet  stems ; j,  small  leaf  of 
sugar  beet,  showing  characteristic  “ curly-leaf  ” condition ; 
fc,  enlarged  section  of  back  of  an  extreme  case  of  “ curly- 
leaf, showing  “ warty  ” condition  of  veins.  Fig.  2. — 
Eutettix  strobi:  a.  Work  of  nymphs  on  lambsquarters ; 
b,  work  of  nymphs  on  sugar  beet.  Fig.  3. — Eutettix  scit- 
ula:  Adult.  Fig.  4. — Eutettix  clarivida:  a,  Wing;  b,  head 
and  pronotum ; c,  d,  genitalia.  Fig.  5. — Eutettix  nigridor- 
sum:  Work  of  nymphs  on  leaf  of  Helianthus.  Fig.  6. — 
Eutettix  straminea:  Work  of  nymphs  on  leaf  of  another 
Helianthus.  Fig.  7. — Eutettix  insana:  Wing.  Fig.  8. — 

Eutettix  stricta:  a,  b , Genitalia 

II.  Work  of  Eutettix  tenella  on  sugar  beet.  Fig.  1. — Three 
“curly-leaf”  beets,  the  result  of  attack  by  Eutettix  tenella, 
and  one  normal  beet  from  the  same  field,  showing  differ- 
ence in  size.  Figs.  2,  3. — “ Curly-leaf  ” beets  as  seen  in 
the  field.  Fig.  4. — Normal  beets  from  same  field 

III.  Work  of  Eutettix  tenella  on  sugar  beet.  Fig.  1. — A large 

beet  becoming  “ curly.”  Fig.  2. — Back  of  a leaf  affected 
by  “ curly-leaf,”  showing  “ warty  ” condition  and  curled 
edges  

IV.  Work  of  Eutettix  tenella  on  sugar  beet.  Fig.  1. — A field  of 

beets  destroyed  by  “ curly-leaf.”  Figs.  2,  3. — Cages  used 

in  the  life-history  experiments 

66 — iv 
IV 


Page. 


34 


44 


44 


4G 


U.  S.  D.  A.,  B.  E.  Bui.  66,  Part  IV. 


Issued  January  27,  1909. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  LEAF  HOPPERS  OF  THE  SUGAR  BEET  AND  THEIR  RELATION 
TO  THE  “ CURLY-LEAF  ” CONDITION. 

By  E.  D.  Ball,  Ph.  D., 

Special  Field  Agent. 

INTRODUCTION. 

Ever  since  the  introduction  of  the  sugar  beet  into  the  intermountain 
region  more  or  less  loss  has  resulted  each  season  from  a condition 
called  “curly-leaf,”  or  “blight.”  (See  PL  I,  fig.  1,  j ; Pis.  II,  III; 
PI.  IY,  fig.  1.)  Around  Grand  Junction,  Colo.,  the  beet  growers 
have  suffered  frequent  losses  from  this  source.  Supt.  George  Austin, 
of  the  Utah  Sugar  Company,  reported  a serious  loss  around  Lehi, 
Utah,  in  1897.  In  1903  the  beet  crop  in  Sevier  County,  Utah,  was 
somewhat  injured,  the  next  year  the  damage  was  worse  and  more 
widespread,  while  in  1905  it  extended  throughout  the  State  of  Utah 
and  the  adjoining  portions  of  Colorado  and  Idaho. 

Until  1905  the  condition  had  been  looked  upon  as  a result  of  some 
fungous  or  bacterial  disease,  or  due  to  a soil  or  climatic  condition. 
During  that  season  it  was  noticed  for  the  first  time  that  a leafhopper 
( Eutettix  tenella  Baker)  was  present  in  large  numbers  in  the  fields 
where  this  damage  was  the  worst,  and  the  writer,  in  connection  with 
his  duties  as  entomologist  of  the  Utah  Agricultural  Experiment  Sta- 
tion, commenced  an  investigation  of  the  insect  and  its  relation  to  the 
damage.  It  was  then  too  late  to  work  out  its  life  history,  so  most 
attention  was  paid  to  a study  of  its  relation  to  the  “ curly-leaf  ” condi- 
tion and  to  experiments  with  remedies.  This  investigation  was  con- 
tinued in  1906  and  1907,  in  cooperation  with  the  Bureau  of  Entomol- 
ogy, and  the  life  history  was  worked  out.  Owing  to  the  small  num- 
ber of  insects  appearing  these  two  seasons,  little  more  was  done  with 
remedies,  but  many  new  facts  were  learned  in  regard  to  methods  of 
attack  and  the  causes  of  the  injury. 

The  writer’s  attention  was  first  called  to  the  “ curly-leaf  ” in 
August,  1900,  by  Prof.  F.  H.  Shaw,  then  chemist  of  the  Grand  Junc- 
tion (Colo.)  Sugar  Factory.  A careful  examination  was  made  at 
this  time  and  again  in  succeeding  years,  but  no  explanation  was  found 

66 — iv 


33 


34 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


for  this  condition.  These  examinations  were,  however,  always  made 
late  in  the  season  after  the  curly-leaf  character  had  become  general 
and  after  the  greater  number  of  insects  had  disappeared.  Examina- 
tion of  the  beets  always  revealed  a few  specimens  of  Eutettix  tenella 
along  with  other  leaf  hoppers  and  miscellaneous  insects,  but  never  in 
sufficient  number  to  cause  suspicion. 

Late  in  June,  1905,  reports  began  to  come  in  to  the  Utah  experiment 
station  of  the  appearance  of  an  insect  in  the  beet  fields  of  the  southern 
and  central  portions  of  the  State,  and  on  July  8 the  writer,  in  com- 
pany with  Mr.  George  Austin,  visited  the  fields  around  Lehi  and  there 
found  the  beet  leaf  hoppers,  associated  with  smaller  numbers  of  false 
chinch  bugs  (Nysius)  and  leafhoppers  of  the  genus  Agallia,  causing 
serious  damage  to  the  young  plants,  especially  in  the  late-planted 
fields. 

From  the  size  of  the  beets  and  the  number  of  the  beet  leafhoppers 
present  when  first  examined  in  1905,  the  prediction  was  made  that  the 
insects  would  not  be  able  seriously  to  retard  the  further  growth  of  the 
beets.  This  prediction  was  based  on  the  ordinary  amount  of  damage 
done  by  insects  of  sucking  habits.  That  the  number  of  insects  found 
would  be  able  to  injure  or  even  seriously  retard  a very  young  beet 
was  recognized,  but  that  the  same  number  could  have  any  appreciable 
effect  on  large  beets  was  contrary  to  all  expectations  based  on  a knowl- 
edge of  similar  attacks  by  Nysius,  Agallia,  and  other  sucking  insects. 

The  trouble  soon  afterwards  appeared  in  the  Cache  Valley,  Utah, 
and  was  under  observation  there  throughout  the  remainder  of  the  sea- 
son, while  several  trips  were  made  to  various  parts  of  the  State. 
Wherever  it  appeared  it  gradually  grew  worse,  and  although  the  year 
1905  started  with  everything  favorable  in  the  early  season,  the  Utah 
beet  crop  fell  below  the  average  about  75,000  tons.  This,  however,  did 
not  anywhere  represent  the  entire  loss,  as  both  sugar  content  and 
purity  of  the  beets  harvested  fell  far  below  the  average,  entailing  fur- 
ther loss  to  the  sugar  companies  and  bringing  the  total  to  more  than 
half  a million  dollars. 

In  Sanpete  and  Sevier  counties,  in  the  southern  part  of  Utah,  a 
large  part  of  the  acreage  was  abandoned  early  in  the  season,  while  the 
rest  barely  paid  the  expense  of  harvesting.  In  Utah  County  the  crop 
varied  from  a total  loss  on  a few  late  fields  to  a full  crop,  with  an 
average  of  more  than  a half  crop  harvested.  In  the  Cache  Valley,  in 
the  northern  part  of  the  State,  the  loss  was  about  one-third  in  tonnage, 
and  in  Weber  and  Boxelder  counties  less  than  that. 

In  1906  a very  small  number  of  leafhoppers  appeared,  and,  as  the 
season  was  cool,  even  where  they  were  most  abundant  little  damage 
was  done.  A careful  study  was  made  of  the  life  history  and  distribu- 
tion of  the  species,  and  a number  of  tests  were  made  of  its  injury  to 
the  beets. 


66— iv 


Bui.  66,  Pt.  IV,  Bureau  of  Entomology,  U.  S.  Dept,  of  Agriculture. 


Plate  I. 


Leafhoppers  (Eutettix  spp.)  and  Their  Work. 

Fig.  1 .—Eutettix  tenella:  a,  Adult;  b,  nymph;  c,  wing;  d,  e,  genitalia;  /,  eggs  (greatly 
enlarged);  g,  section  of  beet  stem,  showing  fresh  eggs  in  place;  h,  same,  showing 
eggs  reaay  to  hatch;  i,  old  egg-scars  on  beet  stems;  j,  small  leaf  of  sugar  beet,  show- 
ing characteristic  “curly-leaf”  condition;  k,  enlarged  section  of  back  of  an  extreme 
case  of  “curly-leaf,”  showing  “warty”  condition  of  veins.  Fig.  2. — Eutettix  strobi: 
a,  Work  of  nymphs  on  lambsquarters;  b,  work  of  nymphs  on  sugar  beet.  Fig.  3. — 
Eutettix  scitula:  Adult.  Fig.  4. — Eutettix  clarivida:  a,  Wing;  b,  head  and  pronotum; 
c,  d,  genitalia.  Fig.  5. — Eutettix  nig ridorsum:  Work  of  nymphs  on  leaf  of  Helianthus. 
Fig.  6. — Eutettix  straminea:  Work  of  nymphs  on  leaf  of  another  Helianthus.  Fig. 
1 —Eutettix  imana:  Wing.  Fig.  8. — Eutettix  strieta:  a,  b,  Genitalia.  (Author’s  illus- 
trations.) 


LIBRARY 

SITY  OF  ILLINOIS 
UREJANA 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


35 


THE  BEET  LEAFHOPPER. 

( Eutettix  tenella  Baker.) 

DESCRIPTIVE. 

The  adult  (PI.  I,  fig.  1,  a)  is  a small,  pale  yellowish-green  species, 
little  larger  than  an  Empoasca  or  Typhlocyba,  with  which  it  might 
easily  be  confused  in  the  field  were  it  not  for  the  stouter  build  and 
greater  activity.  When  fresh  or  when  flying  this  leafhopper  appears 
almost  white,  and  for  this  reason  it  has  often  been  called  the  “white 
fly.”  (Wing,  PL  I,  fig.  1,  c;  genitalia,  PI.  I,  fig.  1,  d , e .) 

The  eggs  (PI.  I,  fig.  1,  f)  are  white,  elongate,  slightly  curved  and 
tapering  at  one  end,  and  are  thrust  into  the  leaf  stem  in  a slightly 
downward  direction.  At  first  they  are  scarcely  visible  (PL  I,  fig. 
1,  g ),  but  as  the  stem  grows  they  are  pushed  out  with  the  opening  up 
of  the  injured  spot  until  at  hatching  time  they  are  often  half  free 
(PL  I,  fig.  1,  h).  After  the  eggs  hatch,  the  egg  scars  continue  to  en- 
large and  remain  throughout  the  season  as  irregular,  elongate,  crater- 
like swellings  (Pl.  I,  fig.  1,  i).  The  eggs  are  deposited  on  all  parts  of 
the  leaf  stem,  usually  one  in  a place.  In  the  cages  they  were  often 
placed  close  together,  very  likely  in  this  case  by  different  insects, 
however,  and  a number  were  insetted  into  the  midrib  and  secondary 
veinlets  of  the  leaf  and  a few  into  the  leaf  margin  near  the  base. 

The  nymphs  (Pl.  I,  fig.  1,  h)  are  very  active,  pale  creamy  white  or 
variously  colored  forms.  The  commonest  form  is  pale  creamy  in 
color  with  a brown  saddle  on  the  middle  of  the  abdomen  and  various 
mottlings  on  the  prothorax  and  wing-pads.  Some  have  the  same  pat- 
tern with  a reddish  ground  color,  more  are  creamy  yellow,  and  occa- 
sionally one  is  seen  with  a broad  and  somewhat  irregular  dark  stripe 
down  the  back.  When  small  the  nymphs  will  be  found  most  com- 
monly down  in  the  unfolding  leaves  at  the  center  of  the  beet,  but  as 
they  grow  older  they  spread  out  over  the  plant. 

FOOD  PLANTS. 

The  original  food  plant  of  this  species  is  still  in  doubt.  In  the 
spring  it  was  found  on  greasewood  (Sarcobatus),  sea-blite  (Dondia), 
several  species  of  Atriplex,  Russian  thistle,  and  rarely  on  other  plants 
of  these  two  families  occurring  on  the  waste  land.  As  these  places 
dried  up,  most  of  the  leafhoppers  went  to  the  sugar  beets  in  the  areas 
under  observation.  In  one  case,  however,  the  species  was  found  in 
some  numbers  on  greasewood  during  egg-laying  time,  which  would 
suggest  this  plant  as  its  original  host.  Its  known  distribution  is  all 
within  the  area  in  which  this  plant  is  abundant. 


36 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


DISTRIBUTION. 

This  leaf  hopper  is  apparently  a native  of  the  southwestern  part 
of  the  United  States.  It  has  been  collected  from  about  the  region 
of  Denver,  Colo.,  south  along  the  edge  of  the  mountains,  through 
New  Mexico,  and  west  through  Arizona,  Utah,  and  southern  Idaho 
to  the  coast  in  California  and  Oregon.  Though  confined  to  the 
mountain  region,  its  distribution  is  restricted  to  the  lower  levels, 
and  it  is  never  taken  op  the  mountains  themselves.  From  this  region 
it  has  not  spread  very  far  up  to  the  present  time.  It  was  taken  at 
Fort  Collins  and  Lamar,  Colo.,  in  1901 — in  one  case  100  miles  north 
of  its  known  habitat,  on  wild  plants,  and  in  the  other  an  equal  dis- 
tance east,  but  was  rare  in  both  situations.  In  Utah  it  has  spread  to 
the  northern  line  of  the  State  and  into  Idaho  as  far  as  that  par- 
ticular beet  area  has  been  extended,  while  it  has  not  as  yet  been  taken 
from  the  wild  plants  north  of  Ogden,  Utah. 

LIFE -HISTORY  STUDIES. 

Search  was  made  for  this  species  as  soon  as  the  growing  season 
commenced  in  the  spring  of  1906,  but  no  specimens  were  discovered 
in  the  Cache  Valley,  Utah,  up  to  the  time  the  beets  came  up.  A 
trip  to  Sevier  County,  Utah,  at  the  time  the  very  earliest  beets 
were  just  showing  (April  22)  failed  toxlisclose  a single  individual, 
either  in  the  beet  fields  or  in  waste  places  or  hedgerows  adjacent  to 
the  beet-growing  districts.  The  first  specimens  discovered  this  sea- 
son were  found  at  Thompsons,  Utah,  May  3,  feeding  on  Russian 
thistle,  and  a few  days  later  the  insect  was  found  on  the  same  plant 
and  on  an  annual  saltbush  (Atriplex)  at  Grand  Junction,  Colo. 

Beet  fields  were  examined  at  Grand  Junction,  Colo.,  May  8,  and 
in  Utah  at  Lehi,  May  9;  Smithfield,  May  12;  Garland,  May  13; 
Lehi,  May  17 ; Corinne  and  Penrose,  May  22 ; and  Provo  and  Lehi, 
June  1,  without  finding  a single  leafhopper  on  any  of  them.  The 
beets  were  not  up  at  Lehi  on  May  9,  nor  at  Smithfield,  but  the  fields 
were  examined  carefully,  especially  where  weeds  were  beginning  to 
appear.  Fields  at  Logan,  Utah,  were  under  observation  during  all 
this  time  and  up  to  July  1,  but  no  leaf  hoppers  were  found. 

RECORD  AT  LEIII,  UTAH. 

On  June  21  a field  was  examined  at  Lehi  in  which  there  was  an 
average  of  one  or  two  leafhoppers  to  a beet.  They  were  all  adults 
and  two-thirds  of  them  females.  The  beets  in  this  field  were  from 
6 to  10  inches  across,  and  no  sign  of  injury  was  observed.  On  exam- 
ining the  other  fields  in  the  valley  a very  much  smaller  number  of 
leafhoppers  was  found.  Some  fields  had  one  individual  to  10  beets, 

0G— iv 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


37 


while  some  had  none  at  all.  The  average  would  not  have  been  more 
than  one  leafhopper  to  25  beets.  They  were  most  numerous  on  the 
higher,  drier  fields,  and  on  the  early  beets.  Two  patches  of  very 
late  beets  close  to  the  first  one  visited  had  no  leaf  hoppers  at  this  time. 

Eight  females  from  this  field  were  dissected,  and  fully  developed 
^sm’s  were  found  in  each  one,  9 in  one,  7 in  another,  and  from  2 to  4 
in  each  one  of  the  others.  Only  large  eggs  could  be  seen  with  the 
lens  used,  and  probably  some  of  these  wpre  crushed  while  being  re- 
moved. The  fact  that  all  females  had  fully  developed  eggs  and  that 
there  were  more  females  than  males  indicated  that  these  adults  had 
been  out  a long  time  and  were  not  new  ones  of  a brood  that  had  just 
flown  in  from  surrounding  wild  land. 

On  June  29  a few  were  found  in  the  late  beets,  but  no  nymphs  were 
found  anywhere. 

July  10  the  adults  were  present  in  about  the  same  numbers  as  be- 
fore, the  females  still  containing  eggs,  and  a few  very  small  nymphs 
were  found. 

July  23  the  adults  were  slightly  less  numerous,  and  the  nymphs 
from  small  to  one-third  grown  and  quite  abundant.  A few  of  them 
were  nearly  grown,  but  no  fresh  males  could  be  found.  More 
nymphs  were  found  on  the  early  beets,  more  “ curly  leaf  ” on  the 
late  ones. 

August  3 the  nymphs  were  mostly  about  two-thirds  grown,  some 
were  small,  and  some  full-grown.  Large  numbers  of  adults  of  the 
new  brood  were  out,  about  half  of  the  leafhoppers  being  adult  at  this 
time. 

August  14  the  adults  were  abundant.  The  leafhoppers  were  nearly 
all  adults  or  large  nymphs,  but  a few  small  nymphs  were  still  to  be 
found. 

On  August  29  the  insects  were  mostly  adult,  males  being  still  in 
the  majority,  but  there  was  still  quite  a number  of  full-grown 
nymphs.  Many  females  were  dissected  and  a few  found  that  had 
from  4 to  7 large  eggs,  but  the  rest  had  no  sign  of  any.  These  few 
were  probably  the  last  remnant  cf  the  over- wintered  brood  of  females. 

September  12  the  adults  were  still  common  and  more  males  than 
females  were  taken  by  sweeping.  Large  nymphs  were  still  present 
in  small  numbers.  Ten  females  were  dissected,  but  no  eggs  found, 
and  the  abdomens  were  all  small.  Evidently  there  was  to  be  no  egg 
laying  for  some  time,  probably  not  that  season. 

Note. — The  season  opened  unusually  late  at  Lehi  in  1906,  and 
these  dates  would  be  from  one  to  two  weeks  late  for  an  ordinary 
season. 

63754— Bull.  66,  pt  4—09 2 


38 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


RECORD  AT  MONROE,  UTAH. 

In  Monroe,  Sevier  County,  the  season  opened  early,  and  the  beets 
were  nearly  all  planted  in  April.  An  examination  April  22,  as  men- 
tioned above,  failed  to  discover  a single  leafhopper. 

On  June  26,  on  a second  visit,  nearly  all  the  beets  were  in  fine 
shape,  with  leaves  touching  in  the  rows,  and  only  lacking  a few 
inches  of  touching  across  rows.  The  leaf  hoppers  were  present  in 
every  patch,  both  adults  and  very  small  nymphs,  and  occasionally  a 
larger  nymph  was  seen.  Mr.  Fred  Gould,  field  superintendent,  said 
that  he  had  observed  the  adults  for  some  time.  There  were  more  leaf- 
hoppers  on  the  older  patches  than  on  the  late  planted  ones,  indicating 
that  they  had  migrated  in  before  the  younger  beets  were  far  enough 
advanced  to  attract  them. 

On  July  25  the  leafhoppers  had  increased  in  numbers,  averaging 
from  10  to  20  to  a beet  on  the  earlier  patches.  Adult  males  were  com- 
mon, showing  that  the  nymphs  had  commenced  to  change  to  adults 
again.  All  stages  of  nymphs  were  still  common,  however. 

On  September  14  the  numbers  of  leafhoppers  were  beginning  to 
decrease.  Several  countings  gave  an  average  of  7 males  to  5 females 
and  5 large  nymphs.  The  dissection  of  a number  of  females  showed 
no  eggs  developed  as  yet,  and  there  seemed  little  doubt  that  they 
would  hibernate. 

OTHER  RECORDS  IN  UTAH. 

A field  belonging  to  a Mr.  Irons  at  Moroni,  Sanpete  County,  was 
visited  June  27,  and  an  average  of  one  leafhopper  to  every  two  beets 
was  found.  Mr.  Irons,  who  is  a very  careful  observer,  said  that  they 
had  been  there  for  some  time.  A careful  search  was  made  for  the 
nymphs,  but  none  was  found.  This  was  by  far  the  Avorst  infested 
field  in  the  county,  the  average  being  less  than  one  insect  to  ten  beets. 

July  26  adults  and  nymphs  were  about  equally  common,  and  few  of 
either. 

In  the  Cache  Valley  and  the  rest  of  the  northern  end  of  the  State 
the  leafhoppers  did  not  appear  in  sufficient  numbers  to  enable  one 
to  make  any  life-history  notes.  On  this  account  all  cage  experiments 
were  transferred  to  Lehi. 

CAGE  EXPERIMENTS,  LEHI,  UTAH. 

The  field  observations  on  life  history  were  all  checked  by  cage 
experiments  (FI.  IV,  figs.  2,  3).  Cages  1 to  3 were  failures,  through 
the  adults  escaping  from  the  material  used.  Later  a very  fine  silk 
scrim  was  used  and  proved  satisfactory  for  the  life-history  work,  but 
was  too  closely  meshed  to  obtain  normal  temperature  and  moisture 
conditions  inside.  All  cages  were  run  in  pairs  on  similar  beets,  one 
with  insects  and  one  without,  as  a check  on  the  injury  to  the  beet, 
co — iv 


LEAF  HOPPERS  OF  THE  SUGAR  BEET. 


39 


Cages  and  5 (glass  globes  upon  beets  about  8 inches  in  diam- 
eter).— On  July  10,  16  adult  leafhoppers,  12  of  which  were  females, 
were  introduced  into  cage  4.  Previous  dissections  had  shown  that  all 
females  were  bearing  eggs,  and  the  presence  of  a very  few  small 
nymphs  in  the  field  proved  that  the  earliest  ones  began  depositing 
eggs  some  time  before.  It  was  therefore  expected  that  some  of  the 
females  introduced  would  begin  depositing  at  once. 

On  July  23  these  cages  were  examined,  and  in  the  one  containing 
the  leafhoppers  the  stems  were  found  to  be  fairly  covered  with  egg 
scars.  Two  of  the  stems  were  removed  and  preserved,  and  found  to 
contain  161  eggs — not  more  than  one-sixth  of  the  total  number  pres- 
ent. A number  of  females  were  seen  in  the  cage,  but  no  nymphs. 

July  27  the  stems  showed  still  more  egg  scars,  and  there  was  quite 
a number  of  small  nymphs  that  had  apparently  been  out  several 
days.  The  insects  had  been  in  the  cage  only  seventeen  days,  so  these 
eggs  must  have  hatched  within  thirteen  to  fifteen  days  from  the  time 
of  laying,  under  the  conditions  found  in  the  cage.  Another  stem 
was  removed  and  preserved,  and  the  rest  left  as  before. 

On  August  3 another  stem  was  removed.  The  eggs  had  almost 
all  hatched  by  this  time.  Some  had  dried  up  and  a few  were  found 
just  ready  to  hatch.  A few  were  sticking  out  of  the  stalk  and  looked 
quite  fresh,  but  were  probably  infertile.  Some  of  the  leaves  had 
wilted  and  died,  and  the  remainder  were  literally  alive  with  small 
to  half-grown  nymphs,  together  with  a few  adults,  no  doubt  the 
remaining  parents. 

These  half-grown  nymphs  were  no  doubt  those  hatched  between 
July  23  and  27,  and  would  thus  be  between  eight  and  eleven  days 
old,  roughly  indicating  a nymphal  period  of  between  sixteen  and 
twenty-two  days  under  these  conditions. 

On  August  14  this  cage  was  visited  again,  and  the  beet  found  dead 
and  dry.  From  appearances  it  had  been  dead  several  days.  The 
few  leafhoppers  that  survived  were  adults  and  large  nymphs.  They 
were  so  few  in  number  that  it  was  impossible  to  tell  whether  they 
were  the  surviving  parents  or  a new  generation,  so  they  were  released. 

Cages  6 and  7 (silk  scrim  2 feet  square). — On  July  23,  18  nymphs 
varying  between  one-third  and  two-thirds  grown  were  introduced 
into  cage  6.  These  were  intended  to  represent  the  larger  ones  found 
in  the  field  at  that  date. 

On  July  27  no  adults  could  be  seen. 

On  August  3 most  of  the  nymphs  had  changed  to  adults.  This 
period  of  eleven  days  was,  then,  more  than  one-third  and  slightly 
less  than  two-thirds  of  the  nymphal  period.  This  gives  about  the 
same  result  as  the  test  in  cage  4. 

Cages  8 and  9 (silk  sorim  with  glass  top). — On  August  3,  40  leaf- 
hoppers wTere  introduced  into  cage  8 ; of  these  23  were  females, 
66— iv 


40 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


apparently  all  fresh,  10  were  males,  and  7 were  large  nymphs,  the 
aim  being  to  get  as  many  of  the  earliest  ones  of  the  maturing  brood 
as  possible  without  introducing  any  belated  ones  of  the  parent  brood. 
By  this  method  it  was  hoped  to  get  the  succeeding  brood,  if  there 
was  to  be  one,  as  soon  in  the  cages  as  it  appeared  in  the  field,  and 
thus  establish  a minimum  time  between  broods. 

On  August  14  this  cage  was  examined,  and  all  leafhoppers  seen 
were  adults.  There  were  no  signs  of  egg  scars  or  of  damage. 

On  August  30  but  few  leafhoppers  could  be  seen,  and  no  egg  scars 
or  damage. 

On  September  12  the  leafhoppers  were  almost  all  gone,  and  no  eggs 
had  been  laid,  either  in  the  cage  or  field,  and  dissection  showed 
that  the  females  had  no  visible  eggs  in  the  abdomen  up  to  date.  It 
was  thought  at  this  time  that  the  adults  would  lay  eggs  in  the  fall 
and  then  die.  Accordingly  a new  lot  was  started,  as  shown  below. 

Cages  10  and  11  (large  lantern  globes). — On  August  30,  30  leaf- 
hoppers were  introduced  into  No.  10,  of  which  12  were  females.  In 
No.  11  one  female  and  several  males  were  introduced.  On  September 
12  no  egg  scars  could  be  found  in  either  cage. 

Cages  13  anti  11+  (silk  scrim  with  a glass  top).— On  September  12, 
20  leafhoppers,  nearly  all  of  which  were  females,  were  placed  in 
cage  13. 

On  October  20  the  field  of  beets  was  harvested.  The  cages  were 
removed  and  the  beets  labeled  and  sent  on  for  examination.  Each 
leaf  and  stem,  and  even  the  parts  of  the  beet  itself  protruding  from 
the  ground,  were  examined  carefully,  but  no  sign  of  any  egg  scars 
could  be  found  on  these  beets  or  on  those  from  the  previous  cages. 
Many  of  the  leafhoppers  were  alive  at  the  time  the  cages  were  re- 
moved, and  there  seems  to  be  no  doubt  that  they  must  hibernate  as 
adults. 

SUMMARY  OF  LIFE  HISTORY. 

By  the  time  the  beets  were  thinned  the  leafhoppers  began  to  appear 
in  the  fields  and  by  the  middle  of  June  were  well  distributed.  They 
gradually  increased  in  numbers  for  some  time  after  this.  Egg  la}dng 
began  at  Lehi,  Utah,  late  in  June  and  continued  until  late  in  August, 
each  female  depositing  about  80  eggs,  the  period  of  deposition  ex- 
tending through  several  weeks,  the  greater  number  of  the  eggs,  how- 
ever, being  deposited  in  the  ten  days  preceding  the  middle  of  July. 
The  nymphs  appeared  in  small  numbers  by  July  10,  and  were  still  to 
be  found  in  small  numbers  in  September.  A great  majority  of  them 
emerged  from  the  eggs  the  last  ten  days  in  July  and  changed  to 
adults  some  twenty  days  later.  The  first  adults  appeared  from  these 
nymphs  the  last  of  July  and  continued  to  increase  in  number  through 
August.  The  egg  stage  in  the  cage  experiments  was  between  thirteen 
and  fifteen  days;  the  larval  stage  between  sixteen  and  twenty-two 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


41 


ECONOMIC  RELATIONS. 

The  first  fact  observed  in  1905  was  that  different  fields  were  affected 
very  differently,  and  much  time  was  spent  in  studying  conditions  in 
an  attempt  to  discover  just  what  combination  of  factors  was  neces- 
sary to  produce  the  “ curly-leaf,”  so  fatal  to  the  beets.  Even  in  the 
worst  fields  examined  there  would  be  here  and  there  a beet  that  was 
apparently  untouched  and  growing  as  usual,  while  in  the  best  fields 
only  here  and  there  could  an  affected  one  be  found. 

As  a result  of  the  season’s  observations  there  seemed  to  be  little 
question  that  the  “ curly-leaf  ” condition  was  the  result  of  the  attack 
of  the  leafhoppers  combined  with  the  effect  of  a very  hot,  early 
season. 

In  many  plaves  it  was  noticed  that  along  the  edges  of  the  fields 
where  the  beets  had  any  shade — such  as  would  be  furnished  by  a 
hedgerow,  or  even  by  a vigorous  stand  of  sweet  clover  on  a ditch 
bank — there  would  be  a marked  difference  for  the  first  few  rows. 
In  Sevier  County,  where  many  of  even  the  early-planted  fields  were 
abandoned  and  where  the  rest  averaged  from  2 to  4 tons  per  acre, 
one  field  was  seen  that  did  not  show  much  damage  and  yielded  12 
tons  per  acre.  This  field  had  a block  of  tall  poplar  trees  on  the  south 
and  a row  of  equally  tall  ones  on  the  west  side.  In  other  places  it 
was  observed  that  the  fields  that  were  the  weediest  had  better  beets 
than  those  that  had  been  well  cultivated.  Under  ordinary  condi- 
tions the  results  in  all  these  cases  would  have  been  just  the  reverse, 
and  the  only  explanation  that  seemed  plausible  was  that  the  shade  of 
the  trees  and  of  the  weeds  kept  the  ground  from  becoming  quite  so 
hot  and  thus  allowed  the  beets  to  overcome  the  effects  of  the  leaf- 
hoppers. In  ordinary  practice  the  beets  are  not  irrigated  until  they 
have  made  considerable  growth;  thus  the  taproot  is  forced  to  de- 
scend for  water,  and  a long,  symmetrical  beet  results,  while  if  watered 
too  soon  the  beets  are  short  and  sprangly.  In  one  place,  in  1905,  it 
was  found  that  the  water  had  escaped  from  a ditch  and  irrigated  one 
corner  of  a field  much  earlier  than  it  had  been  applied  to  the  rest,  and 
this  corner  was  the  only  place  that  was  not  seriously  affected  with  the 
“ curly-leaf.”  In  another  place  the  water  supply  failed  just  as  they 
started  to  irrigate  the  field,  and  the  remainder  was  not  irrigated  until 
a week  later.  The  difference  in  the  amount  of  u curly-leaf  ” on  these 
beets  showed  plainly  to  the  end  of  the  season  just  how  far  the  early 
water  reached.  At  first  these  differences  were  attributed  to  the  effect 
of  the  early  water  on  the  beet  itself,  but  on  further  investigation  a 
number  of  fields  was  found  where  subirrigation  was  depended  upon 
entirely  and  where,  ordinarily,  fine  beets  were  raised.  In  these  fields 
the  taproots  of  the  beets  were  found  to  extend  into  a stratum  of  satu- 
rated soil  and  yet  the  beets  were  badly  affected  and  continued  to  grow 

66—  iv 


42 


SOME  IK  SECTS  INJURIOUS  TO  TRUCK  CROPS. 


worse  throughout  the  season.  The  only  explanation  found  for  that 
condition  was  that,  while  the  beet  had  plenty  of  water,  still  the  top 
soil  was  dry  and  dusty,  and  the  ground  was  as  hot  as  in  an  ordinary 
field,  while  in  the  fields  that  were  irrigated  early  the  evaporation  from 
the  moist  surface  kept  the  temperature  down  until  the  beets  were  large 
enough  to  shade  the  ground.  This  would  also  explain  the  fact  that 
everywhere  in  the  State,  except  in  Sevier  County,  the  late  beets  were 
affected  much  worse  than  the  early  ones.  In  other  portions  of  the 
State  the  early  beets  were  large  enough  to  shade  the  ground  in  the 
rows  by  the  time  the  hot  weather  and  leafhoppers  appeared.  In 
Sevier  County,  on  the  other  hand,  the  hot,  dry  weather  came  on 
earlier  and  the  leafhoppers  were  so  much  more  numerous  that  even  the 
earliest  beets  could  not  withstand  their  attack  when  exposed  to  the 
.full  force  of  the  sun. 

The  unusual  numbers  of  the  beet  leaf  hopper  were  apparently 
largely  the  result  of  a winter  and  spring  favorable  for  the  preserva- 
tion of  insect  life,  as  almost  all  injurious  insects  were  present  in  in- 
creased numbers  during  that  season  (1905).  The  leafhoppers  had, 
however,  evidently  been  increasing  for  several  years  and  had  even 
before  this  reached  destructive  numbers  in  Sevier  County,  as  the 
beet  growers  there  had  been  suffering  increasingly  from  what  they 
called  “ blight  ” for  two  years  previous  to  this,  and  this  increase  in 
the  number  of  insects,  followed  by  a winter  favorable  to  their  sur- 
vival, resulted  in  the  outbreak  of  1905. 

The  leafhoppers  were  present  in  every  field  examined  in  Utah  that 
season,  and  occurred  in  the  greatest  abundance  in  the  areas  in  which 
the  “ curly-leaf  ” was  worst.  The  average  number  of  adults  of  the 
over- wintered  brood  to  a beet  varied  from  3 or  4 up  to  10  or  15,  and 
probably  even  more  than  that  in  Sevier  County,  judging  from  the 
number  found  there  later.  No  serious  damage  was  done  where  there 
were  only  the  smaller  numbers,  and  even  where  the  damage  was  worst 
it  seemed  to  depend  more  upon  how  early  they  appeared  and  the  tem- 
perature and  moisture  of  the  locality  at  that  time  than  on  the  actual 
number  above  an  average  of  possibly  5 or  6 to  a beet.  In  1900  they 
appeared  in  very  small  numbers.  The  field  at  Lehi,  Utah,  where  the 
experiments  were  conducted,  was  by  far  the  worst  found,  and  here 
they  averaged  only  about  1 or  2 to  a beet,  while  the  average  of  the 
valley  would  not  have  been  more  than  1 to  every  ten  or  fifteen  beets, 
and  the  average  of  the  State  was  even  less. 

A field  in  Boxelder  County,  Utah,  was  examined  in  August,  1905, 
in  which  the  leafhoppers  had  recently  appeared  in  large  numbers, 
averaging  100  or  even  200  in  some  places' to  the  beet.  The  beets  were 
large  enough  then  to  shade  the  ground,  and  the  field  was  well  irri- 
gated from  that  time  on.  Almost  no  curling  of  the  leaves  could  be 


00 — iv 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


43 


found  in  this  field,  and  in  the.  fall  the  yield  was  nearly  up  to  the 
average.  This  was  the  only  field  examined  in  which  the  leafhoppers 
did  not  appear  until  after  the. adults  had  hatched  out.  On  the  other 
hand,  many  fields  were  examined  in  which  the  leafhoppers  had  been 
present  early  in  the  season  but  had  almost  disappeared  after  the 
nymphs  had  matured,  and  yet  in  these  fields  the  curling  continued 
to  develop  throughout  the  season  and  the  beets  grew  worse  instead  of 
recovering. 

Spraying  with  kerosene  emulsion  was  tried  on  a field  in  the  Cache 
Valley,  Utah,  in  1905.  This  field  contained  numerous  adults  and 
nymphs  in  all  stages.  Four  nozzles  were  used,  each  one  set  about  18 
inches  above  the  row  and  pointing  obliquely  down  and  forward,  and 
just  in  front  of  them  a bar  drew  the  beet  tops  over  and  caused  the 
leafhoppers  to  jump  just  as  the  spray  struck  them.  An  emulsion 
diluted  with  15  parts  of  water  had  little  effect  on  the  adults,  and 
only  killed  a few  of  the  smaller  nymphs.  Most  of  the  nymphs  would 
kick  about  on  the  ground  and  some  would  become  quite  still,  but  a 
little  later  most  of  them  would  recover  and  hop  away.  An  emulsion 
diluted  with  8 parts  of  water  produced  the  same  effect  on  the  adults 
that  the  weaker  dilution  did  upon  the  nymphs,  and  killed  the  ma- 
jority of  the  nymphs  that  it  struck.  Many  of  the  latter  would,  how- 
ever, escape  the  spray  on  account  of  the  broad  leaves  of  the  beet,  and 
the  results  were  not  considered  entirely  satisfactory. 

In  the  cage  experiments  it  was  expected  that  the  number  of  leaf- 
hoppers necessary  to  cause  “ curly-leaf  ” on  different-sized  beets 
would  be  ascertained,  but  owing  to  the  fineness  of  the  gauze  neces- 
sary to  hold  them  the  temperature  and  moisture  could  not  be  con- 
trolled and  no  “ curly-leaf  ” was  produced.®  The  damp  conditions  of 
the  cages  also  made  it  difficult  to  keep  the  insects  for  any  length  of 
time. 

In  one  experiment  16  leafhoppers,  12  of  which  were  females  ready 
to  deposit  eggs,  were  placed  on  a beet  with  a top  8 inches  in  diameter 

aThis  manuscript  was  originally  prepared  and  submitted  at  the  close  of  the 
season  of  1906.  Some  revision  was  made  to  include  the  important  facts  of  the 
work  of  1907,  but  the  main  discussions,  including  the  above  paragraph,  were 
written  in  1906.  Since  that  writing  “ curly-leaf  ’’lias  appeared  in  cages  arranged 
by  Prof.  E.  G.  Titus  in  joint  investigations  with  the  writer.  Mr.  H.  B.  Shaw, 
assistant  to  Dr.  C.  O.  Townsend,  in  charge  of  Sugar  Beet  Investigations,  Bureau 
of  Plant  Industry,  U.  S.  Department  of  Agriculture,  has  also  succeeded  in  pro- 
ducing “ curly-leaf  ” under  experimental  conditions.  He  writes  me  under  date  of 
October  23,  1908,  that  curly  top  or  “ curly-leaf  ” appeared  in  the  cages  on  the 
experimental  plat  at  Garland,  Utah,  in  which  he  introduced  the  beet  leaf- 
hoppers, and  that  later  he  sent  a number  of  leafhoppers  to  the  office  of  Sugar 
Beet  Investigations,  Bureau  of  Plant  Industry,  where  6 of  them  were  placed  in 
a cage  with  11  young  beets,  9 of  which  showed  distinct  symptoms  of  “ curly- 
leaf  ” within  five  weeks  after  the  insects  were  introduced. 

66— iv 


44 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


and  consisting  of  a dozen  or  more  leaves.  Over  another  beet  of  the 
same  size  a check  cage  was  placed.  Seventeen  days  later  the  eggs 
had  just  begun  to  hatch,  and  already  the  beet  in  the  cage  without  any 
hoppers  was  nearly  twice  the  size  of  the  first  one.  The  beet  on  which 
were  the  leafhoppers  continued  to  grow  for  a week  or  more,  then 
practically  stood  still,  and  on  the  seventeenth  day  it  was  apparently 
smaller  than  when  examined  five  days  before.  Seven  days  later  a 
large  number  of  nymphs  had  hatched  out,  the  outer  leaves  were  dead, 
and  the  rest  looking  sickly;  ten  days  later  than  this  the  cage  was 
examined  again  and  the  beet  was  dead  and  dry,  while  the  beet  in  the 
check  cage  had  again  doubled  in  size.  Twelve  leafhoppers  and  their 
eggs  stopped  the  growth  of  a beet  in  less  than  two  weeks,  and  they, 
together  with  their  progeny,  killed  it  in  less  than  two  weeks  more. 
The  same  number  of  adult  specimens  of  Agallia,  Nysius,  or  Empoasca, 
would  scarcely  have  made  an  impression  on  a beet  of  that  size. 

CHARACTERISTICS  OF  “ CURLY-LEAF.” 

The  first  symptom  of  “ curly-leaf  ” or  “ blight  ” of  the  beet  is  a 
thickening  of  all  the  smaller  veinlets  of  the  leaf,  giving  it  a rough- 
ened appearance  on  the  underside.  This  is  followed  by  a curling  of 
the  edge  (PI.  Ill,  fig.  1)  and  a final  rolling  up  of  the  leaf  (PI.  I,  fig. 

I,  j;  PL  II,  figs.  2,  3;  PI.  Ill,  fig.  2),  the  upper  surface  always  being 
rolled  in.  As  this  progresses  the  small  veinlets  grow  still  larger  and 
more  irregular,  knotlike  swellings  appear  at  frequent  intervals  (PL 
III,  fig.  2),  and  in  extreme  cases  little  nipplelike  swellings  appear, 
extending  to  a height  of  nearly  one-fourth  of  an  inch  (Pl.  I,  fig.  1,  Jc). 
This  will  be  noticed  first  upon  a medium-sized  leaf,  gradually 
spreading  to  the  younger  ones,  while  at  the  same  time  the  beet  almost 
stops  growing  and  a large  number  of  fibrous  roots  are  sent  out  (PL 

II,  fig.  1).  These  roots  are  not  confined  to  two  irregular  lines  as  in 
a healthy  beet.  The  beet  often  continues  in  this  way  throughout  the 
season,  in  bad  cases  it  shrivels  and  dies,  while  in  a few  instances  there 
is  a partial  recovery  and  a new  set  of  leaves,  though  the  sugar  content 
remains  very  low. 

Many  of  the  species  of  this  genus  of  leafhoppers  produce  a 
discoloration  or  distortion  of  the  leaves  of  their  food  plant.  This 
appears  to  be  of  the  same  nature  as  the  work  of  the  gall-forming 
species,  and  is  a process  little  understood.  The  wrinkling  and  folding 
of  the  leaves  by  some  of  the  species  is  very  similar  in  appearance  to 
the  work  of  some  gall-forming  aphides.  Some  species  also  produce 
a change  in  color  similar  to  that  produced  in  many  galls. 

In  the  case  of  Eutettix  strobi  (PL  I,  fig.  2 a,  b)  and  E.  scitula  on 
the  Chenopodium  or  on  the  sugar  beet  and  of  E.  nigridorsum  and  E. 
8trarninea  (PL  I,  fig.  6)  on  the  Helianthus  the  discoloration  appears  as 


60 — iv 


Bui,  66,  Pt.  IV,  Bureau  of  Entomology,  U.  S.  Dept,  of  Agriculture 


Plate  II. 


Work  of  Eutettix  tenella  on  Sugar  Beet. 

Fig.  1. — Three  “curly-leaf  ” beets,  the  result  of  attack  by  Eutettix  tenella , and  one  normal 
beet  from  the  same  field,  showing  difference  in  size.  Figs.  2,  3.—“  Curly-leaf  ” beets  as 
seen  in  the  field.  Fig.  4. — Normal  beets  from  same  field.  (Original.) 


library 

'XY  OF  ILLINOIS 

URBAN/L 


Bui.  66,  Pt.  IV,  Bureau  of  Entomology,  U.  S.  Dept,  of  Agriculture. 


Plate  III. 


Work  of  Eutettix  tenella  on  Sugar  Beet. 

Fig.  1. — A large  beet  becoming  “curly.”  Fig.  2. — Back  of  a leaf  affected  by  “curl y-leaf,” 
showing  “warty”  condition  and  curled  edges.  (Original.) 


LIBRARY 

u:;iv:nsiTY  of  Illinois 

URCANA 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


45 


soon  as  the  little  nymphs  begin  to  feed,  and  this  is  soon  followed  by 
the  distortion  of  the  leaf  in  a certain  definite  way  in  each  case.  That 
this  is  not  caused  by  the  mechanical  injury  of  the  puncture  or  due 
alone  to  the  loss  of  sap  seems  to  be  abundantly  proved  by  the  fact 
that  the  Chenopodium  is  often  attacked  by  other  sucking  insects  in 
much  larger  numbers  without  producing  either  the  red  pigment  or 
the  gall-like  distortion.  The  fact  that  a certain  characteristic  color 
and  appearance  are  always  produced  by  a given  species,  no  matter 
whether  on  a Chenopodium  or  on  a sugar  beet,  and  that  the  color  and 
form  vary  for  the  different  species  of  the  same  genus  even  when 
working  on  the  same  plant,  would  indicate  that  there  is  some  definite 
agency  back  of  it  all.  It  has  also  been  noticed  that  in  all  this  group 
the  greatest  amount  of  damage  is  done  in  hot,  dry  situations. 

Whether  or  not  the  “ curly -leaf  ” condition  is  entirely  the  result  of 
the  change  in  the  beet  caused  by  the  attack  of  the  beet  leaf  hopper  is 
still  an  open  question,  but  that  there  is  some  relationship  between  the 
leafhopper  attack  and  the  “ curly-leaf  ” does  not  seem  to  admit  of  a 
doubt  in  the  light  of  the  facts  brought  out  in  the  investigations.  The 
amount  of  damage  in  a given  valley  was  directly  proportional  to  the 
number  of  leaf  hoppers  present,  the  injury  appeared  only  after  the 
appearance  of  the  leafhoppers,  and  the  “ curly-leaf  ” condition  is 
known  to  occur  only  on  beets  growing  within  the  range  of  this  insect. 

Attention  was  not  called  to  the  damage  early  enough  in  1905  to 
ascertain  whether  or  not  the  “ curly-leaf  ” appeared  before  the  first 
appearance  of  the  nymphs.  At  Lehi,  Utah,  the  “ curly-leaf  ” ap- 
peared very  soon  after  the  first  nymphs.  In  the  Cache  Valley,  Utah, 
the  nymphs  were  common  by  the  time  the  first  curling  was  noticed. 
In  1906  very  careful  watch  was  kept  in  all  parts  of  the  State  for  the 
very  first  sign  of  leaf -curl,  and  in  no  case  did  it  appear  (except  on  the 
mother  beets)  until  after  the  nymphs  began  to  hatch  out.  In  fact,  in 
almost  every  case  examined  the  cast  skins  of  nymphs  could  be  found 
on  the  back  of  curled  leaves,  while  on  healthy  beets  these  were  very 
seldom  found.  In  all  observations  of  both  years  more  leafhoppers 
were  found  on  the  curled  beets  than  on  others.  At  first  this  was 
thought  to  show  a gregarious  habit  in  the  adult,  but  it  may  be  due  to 
the  fact  that  a given  female  lays  most  of  her  eggs  on  a single  plant 
and  the  nymphs  tend  to  remain  there.  In  Eutettix  strobi  and  the 
other  leaf-curling  forms,  where  the  nymphs  are  brightly  colored  and 
depend  on  their  discolored  spots  for  protection,  it  is  not  unusual  for 
a given  nymph  to  pass  its  whole  life  on  a single  leaf,  or  on  two  or 
three  adjoining  ones;  in  most  cases  but  a single  nymph  will  be  found 
on  a plant,  and  sometimes  the  adult  and  the  nymphal  skin  of  each 
stage  may  be  found  under  a single  leaf.  It  is  very  likely  that  the 
same  habit  persists  in  Eutettix  tenella  and  that  this  fact,  in  part  at 


66 — iv 


46 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


least,  accounts  for  one  beet  being  badly  affected  while  the  adjacent 
ones  are  unharmed.  In  the  case  of  Eutettix  strobi  and  its  allies, 
where  most  of  the  leaves  of  a small  plant  are  affected  by  the  dis- 
tortion, the  plant  usually  shrivels  up  and  dies,  but  where  only  one  or 
two  leaves  on  a large  plant  are  distorted  the  plant  does  not  appear 
to  be  affected  at  all,  and  in  no  case  does  the  color  appear  in  any  of 
the  new  leaves.  In  several  cases  small  beets  have  been  seen  in  which 
every  leaf  has  been  deformed  by  the  work  of  strobi , and  they  had 
apparently  stopped  growing. 

In  the  case  of  the  “ curly-leaf,”  however,  the  abnormal  condition 
apparently  spreads  from  leaf  to  leaf  until  finally  the  whole  plant  is 
affected,  even  though  the  leafhoppers  may  have  disappeared  before 
the  process  is  complete.  This  was  abundantly  demonstrated  by  the 
mother  beets  set  out  in  the  spring  of  1906.  These  beets  were  selected 
from  the  best-looking  beets  of  1905,  and  would  naturally  have  been 
ones  that  showed  little  or  no  effect  of  the  “ curly-leaf  ” the  season 
before.  In  every  case  observed  the  first  leaves  sent  up  by  these  beets 
were  as  curly  as  the  average  of  the  year  before,  and  most  of  them 
formed  stunted  lettucelike  heads,  and  later  withered  and  died.  Some, 
however,  survived  through  the  season,  and  a few  sent  up  stunted  blos- 
som stalks,  but  as  a seed  crop  they  were  an  entire  failure.  This  curl- 
ing took  place  before  any  leafhoppers  were  found  in  the  beets,  and 
in  rows  adjoining  young  beets  that  were  not  at  all  affected  and  did 
not  become  affected  during  the  season.  This  would  indicate  that  the 
agency,  whatever  it  may  be,  that  causes  “ curly-leaf  ” remained  in  the 
beet  itself  over  winter  and  was  transmitted  to  the  first  leaves  in  the 
spring. 

In  early  September,  1907,  the  sugar-beet  region  around  Spreckels, 
Cal.,  was  visited  by  the  writer  and  a number  of  cases  of  what  was 
commonly  called  “ blight  ” or  “ curly-leaf  ” were  examined.  These, 
however,  proved  to  be  quite  different  in  character  from  the  “ curly- 
leaf  ” condition  caused  by  Eutettix  tenella.  The  leaves  of  the  beet 
were  found  to  be  covered  with  pale  spots,  the  edges  were  turned  down 
instead  of  up,  and  the  whole  appearance  was  quite  different.  A care- 
ful search  was  made  over  many  acres  for  specimens  of  tenella , but 
none  was  found;  instead  a species  of  Empoasca  was  always  found 
associated  with  this  appearance  of  the  beets.  The  matter  will  be  dis- 
cussed further  in  connection  with  that  species  (p.  51). 

OTHER  RECORDS. 

Prof.  E.  G.  Titus  reports  that  on  a trip  through  the  sugar-beet 
regions  of  the  West  in  September,  1904,  he  found  Eutettix  tenella 
at  La  Grande  and  Echo,  Oreg.  At  La  Grande  little  damage  was  done, 
while  at  Echo  one  field  of  10  acres  was  so  seriously  injured  by  what 

co — iv 


Bui.  66,  Pt.  IV,  Bureau  of  Entomology,  U.  S.  Dept,  of  Agriculture. 


Plate  IV. 


Work  of  Eutettix  tenella  on  Sugar  Beet. 

Fig.  1.— A field  of  beets  destroyed  by  “ curly -leaf.”  Figs.  2,  3. — Cages  used  in  the  life-history 
experiments.  (Original.) 


LIBRARY 

; ;..;r.SITY  OF  ILLINOIS 
URBANA 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


47 


was  then  called  44  blight  ” that  it  was  not  harvested.  Many  of  the 
beets  had  died  and  the  rest  were  small  and  stunted,  while  the  leaf- 
hoppers  could  be  swept  up  in  numbers. 

In  California  44  curlv-leaf  ” conditions  were  seen  by  Professor  Titus 
at  Oxnard  and  Spreckels  and  reported  to  be  quite  serious  on  the  higher 
lands  back  of  Salinas.  Whether  this  was  the  true  44  curly-leaf  ” or  the 
type  found  there  this  year  was  not  determined. 

In  August,  1907,  another  trip  was  made  by  him  through  the  same 
territory  and  a few  specimens  of  Eutettix  tenella  taken  at  Payette, 
Idaho.  Little  damage  was  being  done  that  season,  but  field  men  re- 
ported considerable  loss  in  1905  in  both  Payette  and  Blackfoot,  Idaho. 
A few  E.  tenella  were  taken  at  Union,  Oreg.,  and  Echo,  Oreg.,  in 
August,  1907,  only  slight  damage  showing  in  either  place.  Large 
nymphs  were  taken  with  the  adults. 

In  California  a number  of  places  were  visited  by  Professor  Titus  in 
August,  1907,  but  no  specimens  of  Eutettix  taken.  In  September 
another  trip  through  the  California  districts  was  made,  and  a few 
specimens  of  E.  tenella  were  taken  at  Chino  on  the  13th.  No  very 
definite  cases  of  44  curly-leaf  ” were  noticed. 

ECONOMIC  SUMMARY  AND  PROPOSED  REMEDIES. 

The  44  curly-leaf  ” condition  or  44  blight  ” of  the  sugar  beet,  as  it 
occurs  in  Utah  and  the  surrounding  region,  appears  soon  after  an 
attack  of  the  beet  leafhopper  ( Eutettix  tenella  Baker).  Its  severity 
is  conditional  upon  the  number  of  insects  present,  upon  the  time  of 
their  appearance,  upon  the  size  of  the  beets,  and  upon  the  temperature 
of  the  surface  soil,  together  with  the  temperature  and  moisture  of 
the  surrounding  air. 

More  should  be  known  about  the  places  of  hibernation  and  early 
spring  history  of  this  insect.  It  could  not  be  found  in  the  rubbish 
around  the  fields  in  early  spring,  and  only  a few  specimens  were  found 
in  waste  places  up  to  the  time  they  appeared  on  the  beets.  When  once 
the  place  where  the  greater  number  of  them  pass  the  winter  is  discov- 
ered, it  may  be  possible  to  destroy  them  there  or  on  their  spring  food 
plants  before  they  migrate  to  the  beets.  After  they  have  appeared 
on  the  beets  it  will  be  necessary  to  be  very  prompt  in  the  matter  of 
remedies  if  the  injury  is  to  be  prevented.  A thorough  spraying  with 
kerosene  emulsion  at  a strength  of  1 part  of  the  stock  solution  a to  5 
parts  of  water  would  destroy  most  of  the  insects  that  it  hit,  and  by 
using  a drag  in  front  of  the  nozzles  to  turn  the  leaves  over  and  cause 
the  insects  to  jump,  most  of  them  could  be  reached.  Where  the  insects 

a For  directions  regarding  the  preparation  and  use  of  kerosene  emulsion  see 
Farmers’  Bulletin  327,  U.  S.  Dept,  of  Agriculture,  pp.  20-21,  and  Circular  80, 
Bureau  of  Entomology. 

66 — iv^ 


48 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


were  coming  in  in  numbers  this  spray  would  need  to  be  followed  by  a 
second  one  10  days  later. 

Several  mechanical  devices  have  been  used  to  catch  different  leaf- 
hoppers,  and  no  doubt  several  of  these  could  be  used  against  this  insect 
with  advantage.  The  tar  pan,  or  “ hopper-dozer,”  drawn  over  the 
beets  two  or  three  times  in  the  first  few  weeks  would  capture  a large 
number  of  them.  The  females,  before  the  eggs  are  laid,  are  quite 
heavy  and  do  not  jump  or  fly  as  readily  as  the  males  and  would  be 
^easily  caught.  A modified  form  of  this  machine,  consisting  of  a 
couple  of  tarred  wings  to  be  drawn  along  on  each  side  of  a row  of 
beets,  while  a drag  agitated  the  tops  and  caused  the  insects  to  fly, 
would  probably  capture  more  than  the  simpler  tar-pan. 

If  the  insects  appeared  while  the  beets  were  quite  small,  they  could 
be  largely  destroyed  by  rolling  when  the  weather  was  cold  or  damp 
and  the  insects  sluggish. 

A number  of  preventive  measures  may  be  used  to  assist  the  beets 
in  withstanding  the  attack  of  the  leafhoppers.  In  some  sections  early 
planting  will  produce  beets  large  enough  to  shade  the  ground  by  the 
time  the  beet  leafhoppers  appear,  and  thus  reduce  the  temperature 
below  the  danger  line.  In  a few  places,  like  the  Grand  Junction  dis- 
trict in  Colorado  and  Sevier  County  in  Utah,  early  planting  alone 
would  not  avail,  as  the  insects  appear  soon  after  the  earliest  beets 
come  through  the  ground.  For  such  sections  early  and  frequent  irri- 
gations would  assist  in  keeping  the  ground  cool  until  the  beets  grew 
large  enough  to  shade  it  and  thus  take  care  of  themselves. 

All  preventive  measures  will  depend  for  success  upon  some  method 
of  controlling  the  temperature  in  the  field  so  that  the  ground  may  not 
be  hot  and  dry  at  the  time  the  leafhoppers  appear. 

BIBLIOGRAPHICAL  REFERENCES. 

1895.  Gillette,  C.  P.,  and  C.  F.  Baker. — A preliminary  list  of  tlie  Hemiptera 

of  Colorado. < Bui.  31,  Colo.  Agric.  Exp.  Sta.,  p.  100. 

On  sugar  beets  in  Colorado.  Mention  as  Thamnotettix  tenellus  Uhl.  MSS. 

1896.  Baker,  C.  F. — New  Hemiptera.  <Psyche,  Vol.  VII,  Suppl.,  p.  24. 

Species  described  from  New  Mexico  as  Thamnotettix  tenellus  n.  sp. 

1900.  Forbes,  S.  A.,  and  C.  A.  Hart. — The  economic  entomology  of  the  sugar 
beet.  <Bul.  60,  111.  Agric.  Exp.  Sta.,  pp.  423,  523. 

On  sugar  beets  in  Colorado.  Mention  as  Eutettix  tenella  Bak. 

1903.  Chittenden,  F.  H. — Yearbook  U.  S.  Dept.  Agric.  f.  1902,  p.  730,  1903. 
Mention.  “ Reported  as  injurious  to  sugar  beet  in  Arizona.” 

1906.  Howard,  L.  O.— Yearbook  U.  S.  Dept.  Agric.  f.  1905,  p.  630,  1906. 

Injury  in  Utah.  Mention  as  Eutettix  stricta  Ball. 

1907.  Ball,  E.  D. — Report  of  the  entomologist.  <16tli  Rept.  Utah  Agric.  Exp. 

Sta.,  p.  16. 

Character  of  injury  and  damages  in  1905.  Mention  as  Eutettix  tenella  Bak. 
1907.  Ball,  E.  D. — The  genus  Eutettix.  <Proc.  Davenport  Acad.  Sci.,  Vol.  VII, 
pp.  27-94,  Pis.  I-IV. 

A systematic  and  economic  review  of  the  group,  with  original  illustrations. 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


49 


OTHER  LEAFHOPPERS. 

Seven  species  of  leafhoppers  of  the  genus  Eutettix  besides  tenella 
are  known  to  have  definite  food  plants  related  to  the  sugar  beet,  and 
several  more,  the  food  plant  of  which  is  not  known,  will  probably  be 
found  to  have  similar  habits.  All  of  these  species  will  no  doubt  be 
found  on  the  sugar  beet  as  fast  as  its  cultivation  is  extended  into  the 
regions  where  these  insects  occur.  The  following  species  of  Eutettix 
are  already  known  to  occur  on  the  beet,  and  are  arranged  in  about 
the  order  of  their  present  importance. 

Eutettix  strobi  Fitch. — The  nymphs  of  Eutettix  strobi  are  thickly 
spotted  with  red,  giving  them  a strongly  reddish  appearance.  They 
are  found  on  Chenopodium  album  (PL  I,  fig.  2,  a)  and  are  confined 
strictly  to  the  underside  of  the  leaf.  The  attack  produces  a red  dis- 
coloration and  a curling  of  the  leaf,  which  serves  as  a double  protec- 
tion for  the  insect.  There  are  two  broods  in  a season,  the  nymphs 
appearing  in  late  May  and  early  June  and  maturing  from  the  middle 
of  June  into  July.  The  adults  of  this  brood  are  common  from  the 
middle  of  June  through  July.  Nymphs  appear  again  late  in  July, 
from  which  adults  appear  late  in  August,  and  more  commonly  in 
September.  This  species  was  carefully  studied  through  the  first  brood 
in  1906.  Then  the  area  under  observation  was  pastured  and  the 
record  lost.  The  Colorado  records  agree  with  last  year’s  work  for  the 
first  brood,  and  furnish  data  for  the  second  one.  Prof.  Herbert 
Osborn  a first  called  attention  to  the  red  coloring  of  the  leaves.  It 
has  been  noticed  many  times  since.  This  is,  no  doubt,  the  Allygus  sp. 
of  Bruner.&  Forbes  and  Hart  have  mistaken  the  nymph  for  that  of 
Phlepsius  irroratus  Say.c  The  larva  of  P.  irroratus, however,  is  brown- 
ish and  fuscous  and  lives  on  the  ground.  Eutettix  strobi  has  been  found 
on  beets  (PI.  I,  fig.  2,  b)  in  a number  of  places  in  Colorado  and  Utah, 
nearly  all  of  them,  however,  around  the  margins  of  fields.  In  one 
place  the  insects  had  appeared  on  the  beets  when  they  were  quite 
small,  and  had  been  numerous  enough  to  deform  every  leaf  on  a 
number  of  beets  and  entirely  stop  their  growth. 

Eutettix  scitula  Ball  (PI.  I,  fig.  3). — Eutettix  scitula  is  a white 
species  with  a brown  saddle  and  brown  jironotum.  The  nymphs  are 
of  a powdery  pink  color  and  live  on  the  underside  of  the  Cheno- 
podium  leaf  in  the  same  way  that  those  of  Eutettix  strobi  do,  except 
that  the  discolorations  are  lighter.  This  species  is  apparently 
two-brooded.  The  first  brood  has  been  carefully  worked  out,  but 
only  adults  have  been  observed  in  the  fall.  The  broods  appear  about 
the  same  time  as  those  of  E.  strobi.  This  is  a western  species  occur- 

a Science  Vol.  X,  p.  166,  1887. 

6 Bui.  23,  o.  s.,  L)iv.  Ent.,  U.  S.  Dept.  Agile.,  p.  17,  1891. 

c Bui.  60,  111.  Agric.  Exp.  Sta.,  p.  424,  1900. 

66— it 


50  SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 

ring  in  Colorado  and  Utah  and  has  been  found  on  sugar  beets  only 
at  Grand  Junction,  Colo.  The  adults  of  the  species  are  almost  in- 
variably found  on  poplar  trees,  and  it  seems  probable  that  the  eggs 
are  deposited  on  twigs  of  the  trees  and  that  the  nymphs  drop  to  the 
ground  to  find  a home  on  the  Chenopodium.  The  adults  of  Eutettix 
strobi  and  E.  seminuda  are  often  found  on  trees  and  may  have  the 
same  habit.  In  the  case  of  E.  strobi  and  E.  scitula , nearly  all  in- 
stances of  bad  infestation  have  been  near  trees.  In  the  case  of  E. 
scitida  these  have  been  poplars,  but  two  of  the  worst  instances  of 
injury  from  E.  strobi  were  alongside  apple  trees. 

Eutettix  seminuda  Say. — Eutettix  seminuda  is  a white  insect  with 
a brown  saddle.  It  occurs  from  Kansas  east  to  the  Atlantic  coast. 
The  nymphs  are  pale,  with  a brown  saddle  on  the  abdomen  and  some 
brown  on  the  thorax.  Nothing  is  known  as  to  their  native  food  plant, 
but  from  the  close  relationship  to  the  preceding  species  it  is  likely 
that  it  will  prove  to  be  a Chenopodium.  There  are  two  broods  in  a 
season,  the  first  one  appearing  slightly  earlier  than  in  the  case  of  E. 
strobi.  Eutettix  seminuda  has  been  reported  on  beets  in  Illinois.  It 
does  not  occur  in  the  West,  where  the  writer  has  worked  on  beets. 

Eutettix  clarivida  Van  Duzee  (PI.  I,  fig.  4,  a , 5,  c , d). — Eutettix 
clarivida  is  a green  species  with  four  black  points  on  the  margin  of 
the  vertex.  It  occurs  very  commonly  on  the  shad  scale  ( Atriplex 
confertifolia ) and  on  one  or  two  other  species  of  the  same  genus  in 
the  arid  regions.  It  has  been  found  on  beets  at  Grand  Junction,  Colo. 
The  nymphs  are  green,  with  two  black  spots  on  the  vertex.  The  life 
history  is  not  known. 

Eutettix  insana  Ball  (PI.  I,  fig.  7),  E.  albida  Ball,  and  E.  pau'per- 
culata  Ball  occur  on  different  species  of  Atriplex  in  the  arid  regions, 
and  may  be  expected  to  occur  on  the  beets. 

Eutettix  stricta  Ball  (PI.  I,  fig.  8,  a , b)  is  an  Arizona  species  and 
the  nearest  relative  of  E.  tenella  that  we  know.  There  is  probably 
more  danger  from  this  than  from  any  other  species  of  the  group, 
if  the  sugar  beet  should  be  introduced  within  its  range. 

All  the  species  of  Agallia  in  a given  section  will  be  found  attack- 
ing the  sugar  beet  more  or  less.  Several  of  the  species  seem  to  be 
almost  omnivorous  in  food  habits,  but  where  they  do  show  a pref- 
erence it  is  for  the  relatives  of  the  beet.  For  two  of  the  species 
(cinerea  and  bigelovice)  a definite  food  plant  is  known,  and  in  both 
cases  they  are  close  relatives  of  the  beet.  The  species  of  Agallia  are 
divided  into  two  groups,  based  on  structural  and  life-history  charac- 
ters. In  one  group,  which  includes  sanguinolenta , ulileri , cinerea , and 
bigelovice,  they  seem  to  prefer  warm  and  rather  dry  situations,  the 
adults  hibernating  and  spreading  over  the  beet  fields  in  the  spring  in 
time  to  lay  their  eggs  and  produce  their  single  brood  of  young  there. 

66 — iv 


LEAFHOPPERS  OF  THE  SUGAR  BEET. 


51 


Agallia  sanguinolenta  Prov.  is  the  most  abundant  species  of  the  ge- 
nus in  the  western  country  and  is  found  m all  fields.  Together  with 
A.  uhleri  this  species  has  been  observed  to  do  considerable  damage  in 
the  Arkansas  Valley,  in  Colorado,  and  around  Lehi,  in  Utah.  The 
nymphs  appear  early  in  June  and  mature  in  the  last  half  of  July  and 
the  first  half  of  August,  a few  running  on  through  the  month. 

Agallia  drier ea  Osborn  and  Ball  is  found  almost  exclusively  on  the 
“ shad  scale  ” of  desert  regions,  and  from  this  adults  often  fly 
to  near-by  fields  of  beets.  It  was  common  at  Grand  Junction 
and  Loma,  Colo.,  and  at  Monroe,  Utah.  Under  the  hot  desert  condi- 
tions the  nymphs  appear  in  June  and  mature  the  last  half  of  July, 
while  on  the  beets  they  do  not  mature  until  some  time  later. 

Agallia  bigelovice  Baker  occurs  in  abundance  on  a tall  species  of 
sea-blite  (Dondia)  growing  on  alkaline  soil,  and  has  been  found  in 
the  beet  fields  at  Grand  Junction  and  Palisades,  Colo. 

Agallia  guadripunctata  Prov.  and  A.  novella  Say  belong  to  the 
other  group  of  the  genus  and  pass  the  winter  as  partially  grown 
nymphs,  which  change  to  adults  in  late  May  and  June.  The  nymphs 
appear  again  in  August  and  develop  slowly  until  fall,  when  they 
hibernate.  These  two  species  and  A.  sanguinolenta  are  discussed  by 
Osborn  and  Ball  (Iowa  Experiment  Station  Report  for  1897,  p.  112), 
the  nymphs  and  adults  being  figured  and  the  life  histories  given.  The 
dates  given  there  are,  however,  too  early  for  western  conditions. 
This  group  thrives  best  in  damp  situations  where  rank  vegetation 
abounds,  and  will  not  do  any  serious  damage  to  beets  unless  planted 
alongside  places  of  this  character,  from  which  the  nymphs  can  mi- 
grate in  early  spring.  By  the  time  the  adults  are  mature  and  ready 
to  fly,  the  beets  are  well  started  and  beyond  their  injury. 

Empoasca  sp. — A large  number  of  adults  of  a small  green  Em- 
poasca  were  found  on  sugar  beets  at  Spreckels,  Cal.,  in  early  Septem- 
ber by  Prof.  E.  G.  Titus  and  the  writer.  The  beet  crop  was  not 
seriously  injured,  but  a number  of  beets  were  found  in  which  there 
was  a slight  curling  of  the  leaves  resembling  “ curly-leaf,”  except  that 
in  this  case  the  edges  of  the  leaf  turned  down  rather  than  up,  and 
the  surface  of  the  leaf,  instead  of  being  roughened,  was  covered  with 
small  pale  spots.  This  pale  spotting  of  the  leaves  is  quite  charac- 
teristic of  the  injury  of  the  Empoascas  and  their  relatives  and  is  com- 
monly seen  on  apple  and  rose  leaves.  The  insects  were  all  adults  at 
this  time,  so  that  it  was  impossible  to  be  certain  that  they  had  bred 
on  the  beets,  but  from  the  appearance  of  the  leaves  it  is  probable  that 
they  had.  The  nymphs  of  nearly  all  of  this  group  are  slender,  pale- 
greenish  forms  and  are  found  mostly  on  the  underside  of  the  leaf, 
while  the  white  spots  caused  by  their  punctures  show  more  plainly  on 
the  upper  surface. 

66— iv 


52 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Professor  Titus  reports  finding  an  Empoasca  common  on  beets  at 
Chino,  Cal.,  in  August,  190T,  and  states  that  the  beet  leaves  showed 
the  characteristic  spotted  appearance,  but  that  no  curling  was  noticed. 
In  his  trip  in  1904  Empoascas  were  noticed  in  several  places  in  Cali- 
fornia, and  quite  serious  damage  from  “blight”  or  “curly-leaf” 
was  found  in  a few  places,  but  the  particular  nature  of  the  injury 
was  not  observed. 

The  Empoascas  nearly  all  pass  the  winter  as  adults,  hibernating  in 
rubbish  and  sheltered  places  near  their  food  plants.  In  the  spring 
they  feed  on  anything  that  offers  until  their  food  plants  start,  and 
then  they  gather  on  them,  laying  eggs  in  early  summer.  The  young 
nymphs  feed  on  the  underside  of  the  leaf  and  are  quite  active  and 
keep  out  of  sight. 

Spraying  with  kerosene  emulsion,  1 part  of  the  stock  solution  to  8 
parts  of  water,  proved  to  be  a satisfactory  remedy  for  an  Empoasca 
on  potatoes  in  Iowa  some  years  ago,  and  no  doubt  could  be  used  on  the 
beets  with  success.  Burning  off  rubbish  around  the  field  in  the  late 
fall  would  probably  reduce  their  numbers. 

CONCLUSIONS  IN  REGARD  TO  “ CURLY-LEAF.” 

As  a result  of  the  above  investigations,  it  appears  that  there  are  at 
least  two  distinct  kinds  of  “ curly-leaf  ” that  have  been  confused 
under  one  name.  One,  in  which  the  leaves  become  rough  and  warty 
and  curl  up  and  in  which  the  beet  is  stunted  and  does  not  recover;  the 
other,  in  which  the  leaves  remain  smooth  but  show  numerous  pale 
spots  and  in  which  the  edges  turn  down,  and  in  which,  as  far  as  known, 
the  injury  is  confined  to  the  leaves  attacked.  The  first-mentioned  kind 
of  “ curly-leaf  ” occurs  from  Grand  Junction,  Colo.,  west  to  the  Pacific 
coast  and  is  the  one  that  has  been  seriously  injurious  in  the  inter- 
mountain  region.  This  condition  is  brought  about  by  the  attack  of 
the  beet  leafhopper  ( Eutettix  tenella ),  and  will,  no  doubt,  be  confined, 
for  some  time  at  least,  to  the  southwestern  part  of  the  United  States, 
the  native  home  of  this  insect.  The  second  kind  of  “ curly-leaf  ” has 
been  found  in  California  quite  commonly,  and  doubtless  will  be  found 
to  occur  sparingly  at  least  in  the  eastern  part  of  the  United  States,  or 
wherever  an  Empoasca  attacks  the  sugar  beet. 

Besides  these  two  types  of  this  injury  it  is  quite  possible  that  in 
rare  cases  other  types  with  still  other  causes  have  been  seen  and  not 
recognized  at  the  time  as  distinct.  Investigations  in  the  California 
field  have  been  so  meager  that  it  is  impossible  to  say  as  yet  which 
type  has  caused  the  greatest  injury.  In  the  intermountain  region, 
where  most  of  the  work  has  been  done,  practically  all  the  injury  is 
known  to  have  been  caused  by  the  first  type. 

66— iv 


o 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 
BUREAU  OF  ENTOMOLOGY — BULLETIN  No.  66,  Part,  V. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS 


BY 


F.  H.  CHITTENDEN  and  H.  M.  RUSSELL. 


Issued  January  28,  1909. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1009. 


CONTENTS. 


Page. 

Introduction 53 

Descriptive 54 

Origin  and  distribution 57 

Literature  and  history 57 

Recent  injuries  and  biologic  notes 58 

Early  records 62 

Life-cycle  periods  and  generations 62 

Natural  enemies 63 

Methods  of  control 65 

Resume  of  experiments,  and  conclusions 68 

Summary 69 

Bibliographical  list 70 


V 

ILLUSTRATIONS. 


, Page. 

. 8.  The  semitropical  army  worm  ( Prodenia  eridania ) : Moth,  egg,  egg-mass, 

larvae 54 

9.  The  semitropical  army  worm  {Prodenia  eridania):  Work  of  larvae  on 

“careless  weed”  in  potato  field 59 

10.  The  semitropical  army  worm  {Prodenia  eridania) : Field  of  late  Irish 

potatoes,  showing  vines  entirely  stripped  by  larvae 60 

11.  The  semitropical  army  worm  {Prodenia  eridania):  Larvae  eating  bark  of 

“careless  weed;”  also  nymph  of  spined  soldier-bug  {Podisus  macu- 

liventris),  predaceous  on  larva*  of  Prodenia  eridania 61 

GG — v 


ir 


Page  65,  line  15  from  bottom,  for  fresh  air-slaked  read  freshly  slaked 


U.  S.  D.  A.,  R.  E.  Bill.  06,  Part  V. 


Issued  January  28,  1909. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  SEMITROPICAL  ARMY  WORM. 

( Prodenia  eridania  Cram.) 

By  F.  H.  Chittenden  and  TI.  M.  Russell. 

INTRODUCTION. 

During  the  summer  of  1907  a smooth  or  hairless  caterpillar  (Pro- 
denia eridania  Cram.)  related  to  the  cotton  cutworm  came  under  the 
observation  of  the  junior  author  at  Orlando,  Fla.  It  was  observed 
attacking  the  foliage  and,  in  many  cases,  the  stems  and  fruits  of  all 
forms  of  garden  truck  grown  in  that  vicinity,  the  list  including 
tomato,  potato,  sweet-potato,  eggplant,  pepper,  okra,  collards,  and 
cowpeas.  The  infestation  was  of  considerable  severity,  and  great  in- 
jury was  done  in  fields  and  gardens  in  that  and  in  some  other  regions 
of  Florida,  notably  at  St.  Augustine  and  on  the  west  coast  of  the 
Manatee  River.  What  is  believed  to  be  the  same  species  was  reported 
injurious  in  Porto  Rico  by  Mr.  W.  Y.  Tower.  Aside  from  a brief 
notice  which  has  been  made  of  the  present  invasion  there  does  not 
appear  to  be  any  other  record  of  the  injurious  habits  of  this  species; 
hence  the  following  account  has  been  prepared  for  publication  by  the 
senior  author.  The  chapters  on  recent  injuries,  natural  enemies,  and 
experiments  with  remedies  have  been  compiled  from  the  junior  au- 
thor’s notes.  The  technical  descriptions  of  the  egg  and  larva  have 
been  prepared  by  Dr.  H.  G.  Dyar,  while  other  assistance  in  the  prep- 
aration of  this  article  is  duly  acknowledged  in  its  proper  place. 

In  ordinary  seasons  the  species  under  consideration  confines  itself 
largely  to  weeds,  among  which  are  the  poke-weed,  spiny  amaranth 
or  careless  weed  of  the  South,  and  a wild  Solanum.  It  has  habits 
different  from  those  of  the  northern  cutworms  and  can  scarcely  be 
classified  with  the  climbing  cutworms,  although  it  has  the  climbing 
habit.  It  has  a decided  tendency  to  travel  in  armies  like  the  army 
worms  and  is  practically  confined  to  semitropical  regions.  It  is 
remarkable  as  being  injurious  throughout  the  warm  season  and  breed- 
ing continuously,  there  being  evidentty  at  least  four  generations  a 
year  in  nature. 

66— v 53 


54 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


DESCRIPTIVE. 

The  adult  is  a noctuid  moth,  and  while  the  larva  is  quite  readily 
referable  to  the  genus  Prodenia,  the  moth  has  little  of  the  appear- 
ance of  our  other  two  North  American  species.® 

The  moth. — The  adult  or  moth  has  a wing  expanse  of  nearly  1^ 
inches  (33-38mm)  ; the  fore-wings  are  dull  gray,  sprinkled  and 
dotted  with  brownish  and  black  scales  forming  a pattern  as  shown 
in  figure  8,  d.  There  is  considerable  variability  in  these  markings, 
some  individuals  having  a strongly  marked  reniform  spot,  a very 
prominent  blackish  posterior  marginal  line,  and  a similar  black  line 


Fig.  8. — The  semitropical  army  worm  ( Prodenia  eridania)  : a , Egg-mass  on  leaf ; &, 
egg,  much  enlarged,  showing  lateral  view  at  right  and  top  at  left ; c,  section  of  egg ; 
d,  moth  ; e,  dark  form  of  larva  nearly  grown  ; /,  g,  larva,  full-grown,  a , d-g.  En- 
larged; 6,  highly  magnified;  c,  more  magnified.  (Original.) 

on  the  latero-posterior  margin.  Individuals  also  occur  in  which 
there  is  a straight,  broad,  jet-black  dash  or  band  beginning  at  the 
middle  of  the  fore-wing  and  extending  to  the  lateral  margin.  This 
is  the  nigro fascia  of  Hulst.  The  hind- wings  are  pearly  white  above, 
this  pearly  luster  being  still  stronger  below.  The  body  is  brownish 
gray  and  the  antenna?  are  yellowish  brown. 

The  darkest  forms  of  this  species  are  marked  very  much  as  in  the 
genus  Acronycta. 

The  eggs. — The  eggs  are  deposited  in  irregular  masses,  as  shown 
in  figure  8,  a , closely  placed  together,  sometimes  in  two  layers  and 

° Prodenia  omithogalli  Guen.  (“cotton  cutworm”)  and  P.  comrneUnw  S.  & A. 


GO — V 


THE  SEMITKOPICAL  ARMY  WORM. 


55 


covered  with  whitish  down,  from  the  body  of  the  female.  They  are 
distinctly  green  when  first  deposited  and  have  the  appearance  illus- 
trated at  b and  c. 

The  larva. — The  caterpillar  resembles  that  of  the  other  two  species 
of  Prodenia  sufficiently  to  be  naturally  referred  to  that  genus,  and 
it  is  subject  to  similar  variation  in  color.  The  ground  color  is  dark 
grayish  in  pale  individuals  and  nearty  black  in  the  dark  forms. 
These  latter,  especially  when  approaching  maturity  in  the  penulti- 
mate stage,  are  sometimes  so  dark  as  to  resemble  Mamestra.  The 
body  is  ornamented  with  a narrow,  slightly  interrupted,  median  yel- 
low longitudinal  dorsal  stripe,  a similar  slightly  wider  dorso-median 
stripe,  and  a wide  and  brighter  yellow  substigmatal  stripe,  which 
becomes  obscured  in  the  thoracic  segments  of  the  penultimate  stage. 
In  the  very  dark  forms  the  triangular  velvety  dorsal  spots  character- 
istic of  the  genus  can  scarcely  be  seen,  and  in  the  paler  forms  they  are 
seldom  as  distinct  as  in  the  other  two  species.  When  full-grown  the 
larva  measures  about  an  inch  and  a fourth  to  an  inch  and  a half  in 
length  (25-37mm),  and  the  width  varies  from  one-fourth  of  an  inch 
to  a little  larger.  The  head  measures  nearly  2.5mm. 

The  mature  larva  is  illustrated  at  f and  g of  figure  8 and  a dark 
form  nearly  grown  at  e. 

The  pupa. — The  pupa  resembles  closely  that  of  Prodenia  comme- 
lince.  The  head  and  abdomen  are  well  rounded.  The  color  is 

mahogany-brown,  with  the  head,  spiracles,  and  anterior  edges  of  the 
abdominal  segments  darker.  The  surface  is  smooth  and  shining, 
with  the  anterior  edges  of  the  abdominal  segments  finely  punctured. 
The  anal  segment  terminates  in  a two-spined  cremaster-like  process. 
Length,  16-18  mm;  width,  5-6  mm;  length  of  head  to  end  of  the  wing- 
cases,  10mm. 

The  following  technical  description  of  the  egg  and  larval  stages 
was  kindly  contributed  by  Dr.  H.  G.  Dyar. 

TECHNICAL  DESCRIPTION  OF  THE  EGG  AND  LARVAL  STAGES. 

The  egg. — Hemispherical,  smooth,  pale  green,  shining;  ribs  very  fine, 
obscure,  numerous,  ill-defined,  radiating  from  the  micropyle;  cross-striae  imper- 
ceptible. Diameter,  0.6mm.  Laid  in  a patch,  covered  by  a thin  layer  of  whitish 
wool. 

Stage  I. — Head  rounded,  bilobed,  mouth  pointed,  shining  greenish-black ; 
eyes  black,  mouth  brown ; width  about  0.3mm.  Body  robust,  uniform,  joint  12 
slightly  enlarged,  feet  of  joints  7 and  8 a little  smaller  than  the  others  and  not 
used  in  walking ; translucent  greenish,  cervical  shield,  leg  plates,  thoracic  feet, 
anal  plate,  and  the  large  round  tubercles  shining  black ; tubercles  i and  ii  of 
joint  12  in  a square ; setae  rather  coarse,  moderate,  black,  simple. 

Stage  II. — Head  rounded,  slightly  bilobed,  the  vertex  level  with  joint  2,  shin- 
ing luteous,  blackish  shaded  over  the  vertices  of  the  lobes;  ocelli  black,  mouth 
brown,  width,  0.4 mm.  Body  somewhat  thickened  at  joints  5 and  12,  feet  normal, 
equal ; greenish  luteous,  cervical  shield  and  anal  plate  blackish  infuscated ; 


56 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


tubercles  rather  large,  low-conical,  black ; leg  shields  slightly  smoky ; tubercle 
vi  present ; a large  red  blotch  around  tubercles  i and  iv  on  joints  5 and  12 ; 
setae  short,  black,  stiff ; traces  of  a white  dorsal  line  showing  especially  by  the 
cut  between  the  red  blotches  at  tubercle  i of  joint  5 ; no  other  lines. 

Stage  III . — Head  rounded,  the  vertex  just  within  joint  3,  pale  reddish  over 
the  lobes  and  sides,  luteous  on  the  face,  shining,  very  small  in  proportion  to  the 
body ; width,  0.6 mm.  Body  robust,  slightly  thickened  at  joint  5,  more  so  at 
joint  12 ; feet  normal ; pale  green ; a straight  dorsal  and  a subdorsal  white 
line  and  traces  of  a broken  lateral  one ; subventral  region  slightly  pale,  without 
defined  line;  tubercles  small,  black;  a large,  vinous,  somewhat  elevated  blotch 
on  tubercles  i and  iv  on  joint  5 and  on  tubercle  i on  joint  12,  more  diffusely 
about  the  spiracle  on  joints  11—12;  anal  feet  reddish;  cervical  shield  small, 
infuscated,  cut  by  three  white  lines ; anal  plate  blackish ; thoracic  feet  blackish, 
abdominal  ones  greenish. 

Stage  IV. — Head  rounded,  rather  quadrate,  not  notched,  the  clypeus  high, 
vertex  even  with  joint  2;  pale  red,  paler  on  the  clypeus,  ocelli  and  antennae 
dark;  width  1.0 mm.  Body  robust,  thickened  at  joints  o and  12,  feet  equal; 
blackish  olivaceous,  dorsal  and  subdorsal  lines  straight,  yellowish  white,  edged 
with  vinous  dottings;  traces  of  a lateral  line;  subventral  region  paler  below 
the  spiracles,  especially  after  joint  5;  large  blackisli-red  blotches  at  tubercles 
i and  iv  on  joint  5 and  on  joint  12  and  tubercle  i and  stigmatally  on  joints  11-12; 
white  dotting  in  the  ground  color  most  conspicuous  stigmatally ; thoracic  feet 
black,  abdominal  ones  pale,  anal  pair  reddish. 

Stage  V. — Head  quadrate,  rounded,  slightly  bilobed,  shining  light  red-brown, 
the  clypeus  high;  ocelli  and  setae  black;  width,  1.6mm.  Body  thickened  at 
joints  5 and  12,  feet  equal,  normal,  the  abdominal  ones  pale,  slightly  infuscated, 
the  thoracic  ones  black-ringed ; dark  gray  to  black,  strigose-dotted  with  white : 
dorsal  line  narrow,  subdorsal  broader,  straight,  even,  yellowish  white,  centered 
with  reddish  mottlings,  cutting  the  sooty-black  cervical  shield,  but  not  the  anal 
plate;  a quadrate  black  patch  between  the  lines  on  joint  5,  a small  angular  one 
next  the  subdorsal  line  on  all  the  other  segments,  large  on  joint  12  and  shaded 
across;  a narrow  white-dotted  lateral  line,  scarcely  different  from  the  dots  of 
the  ground  color ; subventral  band  straight,  yellow-white,  broad,  broken  at  joint 
5,  reddish-filled  around  the  spiracles,  black  spots  at  tubercles  iii  with  a distinct 
white  dot  below ; subventral  region  of  thorax  blackish,  of  abdomen  paler,  white- 
dotted. 

Stage  VI. — Head  rounded,  quadrate,  about  as  high  as  wide,  slightly  bilobed, 
the  vertex  level  with  joint  2;  clypeus  high  and  large;  red-brown,  darker 
reticulate,  mouth  parts  concolorous,  ocelli  black ; width  2.1  to  2.4 mm.  Body 
robust,  cylindrical,  tapering  from  joint  5 to  joint  2,  the  head  small;  joint  5 
slightly,  joint  12  distinctly,  enlarged  and  abruptly  tapered  to  joint  13;  black, 
strigose-dotted  with  white;  cervical  shield  deep  black,  white-dotted,  cut  by  three 
white  lines;  anal  plate  similar,  small,  cut  by  the  dorsal  line  only;  dorsal  line 
narrow,  black-dotted  and  broken,  yellowish  white,  reddish  on  the  centers  of  the 
segments;  subdorsal  line  broader,  straight,  yellow-wliite,  reddish  centered  on 
the  segments,  with  a median  row  of  gray  dots,  but  not  incised  on  the  margins; 
a row  of  segmental  black  triangles  above  it,  free  of  white  dots,  largest  on  joint 
5,  the  one  on  joint  12  now  scarcely  larger  than  that  on  joint  11;  upper  half  of 
the  lateral  area  grayer,  with  many  white  dots,  lower  half  blacker,  with  few 
dots  on  joints  5 to  13,  separated  by  a row  of  brighter  dots  representing  the 
lateral  line;  on  joints  2 to  5 this  distinction  is  weakly  developed;  spiracles  in  a 
blacker  shade  with  a white  dot  above  tubercle  iv ; substigmata  1 band  broad, 
even,  undulate,  weak  and  broadly  gray,  centered  on  joints  2 to  5,  fading  out  at 


og — v 


THE  SEMITROPICAL  ARMY  WORM. 


57 


joint  5,  sharply  reappearing  at  joint  5 posteriorly,  then  pale  yellow,  centered 
with  blackish  mottlings  at  the  centers  of  the  segments  and  red  above  these; 
subventral  region  black-shaded,  strongly  so  on  joints  2 to  5,  weakly  on  the  ab- 
domen, white-dotted,  paling  to  the  venter;  thoracic  feet  dark  brown,  the  ab- 
dominal ones  pale  brown,  shining;  a single  cylindrical,  round-tipped  neck  gland 
reaching  to  the  end  of  the  labial  palpi ; crochets  of  abdominal  feet  in  a single 
row,  dark ; tubercle  iv  slightly  above  middle  of  spiracle  on  joint  7.  [Harrison 
G.  Dyar.] 

ORIGIN  AND  DISTRIBUTION. 

This  is  a Lower  Austral  form  and  probably  of  tropical  origin.  In 
the  National  Museum  are  specimens  from  Cocoanut  Grove,  Crescent 
City,  and  Orlando,  Fla.  The  species  is  also  recorded  from  Talla- 
hassee, and  reported  from  St.  Augustine  and  the  region  about  the 
Manatee  River  in  Florida.  From  Texas  we  have  specimens  from  Bos- 
que County  (Belfrage)  and  Dallas,  and  there  are  specimens  col- 
lected at  Pernambuco,  Benito  Province,  Brazil,  by  Mr.  Albert  Koebele. 
Dr.  J.  B.  Smith  records  the  insect  from  Georgia  and  Central  and 
South  America,  and  Grote  records  it  from  California.  This  indi- 
cates a range  extending  from  Brazil  to  Mexico,  Central  America,  and 
the  Antilles,  and  from  Florida  westward  through  the  Gulf  Region  and 
Texas  to  California. 

LITERATURE  AND  HISTORY. 

Considering  the  fact  that  this  species  is  really  common  in  the 
South  and  that  it  feeds  gregariously  and  voraciously,  it  is  somewhat 
remarkable  that  it  has  not  hitherto  attracted  attention  by  its  depre- 
dations. The  moth  was  described  by  Pierre  Cramer  in  1782. 1 a 
Its  natural  food  plants  were  known  to  Smith  and  Abbot,  who  wrote 
of  it  in  their  classic  work  published  in  1797.2  The  illustration  ac- 
companying that  work,  though  over-colored  as  usual,  depicts  a per- 
fectly recognizable  moth  of  this  species  but  a too-brilliant  and  light- 
colored  larva.  Light  and  dark  forms  of  the  moth  are  figured.  The 
species  is  mentioned  as  Phalcena  phytolaccot  and  is  compared  with  the 
related  Proclenia  commelince  and  Lapliygma  frugiperda , which  form 
the  subject  of  the  two  plates  and  pages  immediately  preceding  the 
account  of  phytolaccce. 

As  Smith  and  Abbot’s  work  is  not  accessible  to  many,  the  following- 
copy  of  their  account  of  this  insect  is  republished : 

Phalcena  phytolaccce.  Poke-weed  motb. 

Phytolacca  decanclra.  Linn.  Virginian  poke-weed. 

Ph.  Noctua  spirilinguis  cristata,  alis  deflexis:  primoribus  fusco  striatis 
puncto  obscuro  margine  postico  nigro  maculato ; anteriori  punctate. 

® Numbers  in  superior  type  refer  to  corresponding  numerals  in  the  appended 
bibliographical  list  (p.  70). 

66— v 


58 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Feeds  on  the  Poke,  Careless,  &c.  It  went  into  the  ground  July  the  5th,  and 
came  out  the  16th.  I once  met  this  caterpillar  in  such  abundance,  that  among 
a great  quantity  of  Poke  plants  there  was  scarcely  a single  leaf  untouched ; 
most  of  these  caterpillars,  however,  were  fly-blown  by  a kind  of  Ichneumon. 
The  moth  is  rare. 

This  is  allied  to  our  Ph.  frugiperda  and  Gommelinw.  Between  the  under 
wings  of  all  these  there  is  the  greatest  affinity.  Their  pupae  too  are  of  a 
similar  bright  red  color,  and  their  smooth-striped  caterpillars  have  much 
resemblance  to  each  other. 

RECENT  INJURIES  AND  BIOLOGIC  NOTES. 

Oil  May  14,  1907,  this  species  was  observed  on  the  leaves  of  tomato 
in  the  truck  garden  of  Mr.  C.  M.  Berry,  at  Orlando,  Fla.,  where  it 
was  eating  holes  in  the  leaves.  Numbers  of  plants,  here  and  there, 
were  infested  and  in  most  cases  the  entire  plant  was  injured.  The 
same  larva  was  observed  on  pokeweed  ( Phytolacca  decandra ),  and 
afterwards  on  spiny  amaranth  ( Amaranthus  spinosus).  By  May  20 
the  larvae  were  scattering  and  had  grown  rapidly,  some  being  an 
inch  long.  While  young,  these  larvae  feed  on  the  underside  of  the 
leaf,  but  with  larger  growth  some  were  noticed  feeding  on  the  upper 
surface  as  well. 

May  24  an  egg-mass  was  found  on  a leaf  of  the  spiny  amaranth, 
laid  in  two  sections  on  the  under  surface,  one  on  each  side  of  the 
midrib.  One  mass  had  hatched  at  this  time  and  the  larvae  were  be- 
ginning to  eat  pinlike  holes  through  the  leaf. 

On  July  3 a field  of  Irish  potatoes  wTas  found  to  be  very  badly  in- 
fested b}^  these  larvae.  They  were  now  nearly  full-grown  and  had 
stripped  the  potato  vines,  many  being  observed  crawling  away  from 
the  field  in  all  directions.  On  one  side  they  infested  a garden  at 
least  600  feet  away,  and  were  feeding  upon  eggplant,  pepper,  okra, 
and  castor-oil  plants. 

Some  interesting  notes  were  made  on  the  abundance  of  this  species 
in  this  potato  field.  On  a single  young  plant  of  Amaranthus,  41 
larvae  were  counted,  and  as  many  as  314  on  a plant  measuring  6 feet 
in  height.  A careful  estimate  of  the  larvae  on  10  plants  of  careless, 
weed,  not  over  6 feet  in  height,  gave  a total  of  1,300  individuals. 
(See  fig.  9.) 

To  illustrate  the  voracity  of  these  larvae,  where  any  potatoes  were 
exposed,  they  were  soon  covered  by  the  larvae  and  the  entire  contents 
eaten  out  so  that  they  were  rendered  worthless  in  about  ten  minutes. 
About  this  same  date,  July  3,  the  larvae  were  reported  making  quick 
work  of  amaranth ; whenever  a branch  became  broken  from  any 
cause,  larvae  entered  at  the  break  and  excavated  tunnels  several 
inches  in  length.  Pokeweed  was  entirely  stripped  of  leaves,  the 
stalks  and  the  shoots  being  eaten  off  at  the  outer  end.  Potatoes  dug 

oo — v 


THE  SEMITROPICAL  ARMY  WORM. 


59 


at  this  time  were  frequently  found  full  of  holes,  the  work  of  these 
larvae.  The  following  day,  July  4,  the  amaranth  was  almost  com- 
pletely denuded,  illustrating  the  rapid  work  of  this  species  when  in 
large  numbers  (see  figs.  10,  11).  By  July  8 the  larvae  had  almost 
completed  their  work  in  the  field,  after  having  eaten  everything 
clean.  Many  were  full  grown  and  had  commenced  to  enter  the 
ground.  July  9 the  potato  field  was  stripped,  the  vines  were  dead 
and  dry,  and  the  larvae  had  almost  disappeared.  The  ground  was 
full  of  pupae,  none  of  them  at  a greater  depth  than  4 inches,  and  in 


Fig.  9. — The  semitropical  army  worm  ( Prodenia  eridania ) ; Work  of  larvae  on  “ careless 
weed  ” in  potato  field  ; 311  larvae  were  on  this  plant  when  photographed.  (Original.) 

many  cases  only  2 inches.  Upon  digging  into  the  hills,  it  was  found 
that  they  did  not  average  more  than  four  good-sized  potatoes  to  the 
hill,  and  in  many  cases  these  had  been  rendered  useless  by  the  inroads 
of  the  larvae.  (This  crop  averaged  small  because  of  late  planting.) 

Many  larvae  were  found  feeding  on  sweet  potatoes  at  Mr.  John  M. 
Cheney’s  place  at  this  time,  most  of  them  still  in  young  stages.  A. 
few  fully  matured  larvae  also  were  found,  showing  the  overlapping 
of  the  two  generations;  in  fact,  observations  conducted  both  in  the 

66— v 

64752— Bull.  66,  pt  5—09 2 


60 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


field  and  at  the  insectary  at  Washington,  D.  C.,  show  that  this 
species  is  undoubtedly  a continuous  breeder,  as  in  the  case  of  the 
variegated  cutworm  ( Peridroma  margaritosa  Haw.),  the  larvae  being 
present  in  the  field  throughout  the  long  summer  season  of  the  South. 

July  30,  by  request  of  the  county  commissioner,  Mr.  H.  H.  Dick- 
son, the  junior  author  went  to  the  County  Home  and  found  a sweet- 
potato  patch  badly  infested,  thousands  of  larvae  present,  and  the 
leaves  turning  brown  and  drying  out.  Superintendent  Harris  stated 
that  an  earlier  brood  did  great  damage  to  cowpeas,  but  this  could 
not  be  verified  by  specimens.  In  the  sweet-potato  field  the  larvae 
started  on  the  south  side  and,  after  stripping  the  first  four  or  five 
rows,  moved  over  to  the  next  rows  and  eventually  infested  the  entire 


Fig.  10. — The  semitropical  army  worm  (Prodenia  eridania)  : Field  of  late  Irish  potatoes 
showing  vines  entirely  stripped  by  larvae;  Orlando,  Fla.,  July  6,  1907.  (Original.) 


field.  A Mr.  Porter,  near  the  County  Home,  reported  5 acres 
stripped  in  three  da}rs  after  the  larvae  were  noticed  at  work,  these 
having  started  at  one  side  of  the  field  and  swept  it  clean.  The 
larvae  of  a third  generation  were  observed  at  Mr.  Chene}T’s  place  at 
this  time;  most  of  them,  however,  had  already  gone  into  the  earth 
to  transform. 

August  3,  adults  that  had  pupated  about  July  25  began  to  emerge. 
Thus  the  pupal  period  occupied  about  nine  days.  At  this  time  a 
number  of  young  larvae  were  noted  feeding  upon  amaranth,  wild 
Solanum,  and  castor-oil  plants.  When  disturbed  they  dropped  and 
hun<r  bv  threads. 


THE  SEMITROPICAL  ARMY  WORM. 


61 


By  the  first  of  September  Mr.  Cheney’s  patch  of  sweet  potatoes  was 
entirely  free  from  this  insect,  evidently  owing  largely  to  parasites 
and  to  the  spraying  with  arsenate  of  lead. 

August  30,  1907,  Mr.  Wm.  Donnell,  St.  Augustine,  Fla.,  reported 
that  a cutworm,  which  he  identified  as  this  species,  had  been  very 
destructive  in  that  region,  being  especially  abundant  on  beets,  and 


Fig.  11. — The  semitropical  army  worm  ( Prodenia  eridania)  : Larvae  eating  bark  of  “ care- 
less weed  also  nymph  of  Podisus  maculiventris,  predaceous  on  the  larvae.  (Origi- 
nal.) 

later  affecting  cabbage,  carrots  (by  eating  the  tops),  and  some  other 
plants,  its  operations  being  most  noticeable  at  night. 

Mr.  E.  L.  Worsham,  while  employed  by  this  Bureau,  noticed  this 
species  on  the  west  coast,  near  the  Manatee  Diver,  in  Florida,  and 
reported  it  working  quite  extensively  in  that  region  in  August. 

On  November  23,  1907,  an  egg-mass  was  found  on  ppkeweed  at 
Dade  City,  Fla.,  and  December  2 another  was  observed,  from  which 
66— v 


62 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


the  larvae  hatched  December  4.  These  molted  between  December  10 
and  13,  while  being  transported  to  Orlando,  but  soon  died,  as  frost 
killed  off  the  food  plants. 

July  25,  1908,  Mr.  H.  IT.  Dickson  asked  for  a remedy  to  apply 
against  the  larvae  on  sweet  potatoes  at  the  Orlando  Truck  Farm. 

Egg-masses  received  May  24,  1907,  hatched  at  that  time  and  the 
larvae  entered  the  earth  in  the  rearing  cage  June  19.  In  dry  sand  the 
pupae  were  found  at  a considerable  depth,  but  in  moist  sand  they 
were  found  barely  under  the  surface. 

July  8 larvae  in  the  rearing-cage  were  almost  full  grown.  Larvae 
hatching  from  egg-masses,  and  others  a few  days  old,  were  also 
found  in  abundance  on  sweet-potato  plants.  As  soon  as  hatched 
they  separate,  feeding  on  the  leaf  on  which  the  egg-mass  was  laid, 
perforating  the  underside  full  of  minute  holes,  and  leaving  only  the 
upper  epidermis,  which  turns  browm.  On  growing  larger  they  sep- 
arate, as  in  the  case  of  most  caterpillars,  except  those  of  peculiarly 
gregarious  habit,  and  soon  become  widely  scattered.  Even  when 
abundant  it  is  common  to  see  eight  or  a dozen  on  the  underside  of  a 
single  leaf,  and  frequently  as  many  as  an  hundred.  Occasionally  a 
nearly  full-grown  larva  feeds  on  the  upper  side  of  a leaf.  In  many 
cases  large  larva?  were  found  hiding  during  the  day  at  the  bottom  of 
furrows. 

June  15,  1908,  the  larvae  of  this  insect  were  found  to  be  very  abund- 
ant at  Orlando,  Fla.,  in  one  part  of  the  town  feeding  on  pokeweed, 
and  in  another  on  amaranth. 

EARLY  RECORDS. 

Among  the  records  of  the  Bureau  of  Entomology  is  one  of  May  22, 
1887,  when  larvae  and  pupa?  were  received  from  Mr.  E.  A.  Schwarz 
with  report  that  the  species  was  ver}^  injurious  to  the  eggplant  at 
Cocoanut  Grove,  Fla. 

In  September,  1905,  Mr.  F.  C.  Pratt  sent  to  the  Bureau  a large 
colon}^  of  the  larvae  found  feeding  on  pokeweed  at  Dallas,  Tex.,  the 
moths  from  which  began  to  issue  September  26. 

LIFE-CYCLE  PERIODS  AND  GENERATIONS. 

Larvae  mailed  from  Orlando,  Fla.,  July  3,  arrived  at  Washington, 
I).  C.,  July  5 and  began  to  enter  the  earth  for  pupation  the  following 
day.  On  the  16th  two  had  transformed  to  pupae,  on  the  day  follow- 
ing three  more,  and  the  remainder  transformed  within  a week.  This 
experiment  shows  a pupal  period  of  about  9 days,  allowing  1 day  for 
the  larva?  in  the  earth  before  pupating.  The  weather  was  quite  hot. 
In  a cooler  temperature  in  August  the  pupal  period  required  11  to 
13  days. 

The  moths  hatched  from  different  lots  were  separated  and  the  egg- 
period  observed.  In  one  case  this  lasted  from  August  8 to  12,  or 

oo — v 


THE  SEMI  TROPICAL  ARMY  WORM. 


63 


4 days,  and  in  another  case  from  July  18  to  22,  or  4 days.  In  the 
first  instance  the  temperature  averaged  between  76°  and  80°  F.  and 
in  the  second  from  80°  to  88°  F.  Evidently  this  is  the  maximum 
period. 

As  regards  the  duration  of  the  entire  life  cycle,  it  was  noticed  that 
eggs  deposited  July  3 produced  caterpillars  on  the  9tli,  or  in  6 days. 
These  penetrated  the  earth,  being  full-grown,  on  the  26th,  making  the 
entire  life  period  of  the  larvae  17  days.  They  began  to  issue  as  moths 
August  5.  This  gives  a total  period  for  the  life  cycle  of  31  days  for 
extremely  hot  weather.  In  an  ordinary  outdoor  summer  tempera- 
ture the  period  would  be  about  35  days,  or  5 weeks. 

Our  rearing  records  are  not  quite  as  accurate  as  could  be  desired, 
owing  to  unfortunate  conditions  at  the  insectary  and  to  three  changes 
in  the  office  force  during  the  time  when  the  insect  was  under  observa- 
tion. There  were,  however,  positively  four  generations  here,  and 
about  the  same  number  was  observed  at  Orlando.  There  is  also 
the  possibility  of  an  earlier  fifth  generation  in  nature.  The  exact 
periods  for  the  appearance  of  these  should  be  recorded  in  the  field. 

NATURAL  ENEMIES. 

The  unusual  abundance  of  this  species  at  Orlando,  Fla.,  during  the 
season  of  1907  afforded  a most  excellent  opportunity  for  the  study 
of  its  insect  natural  enemies.  These  came  under  observation  as  early 
as  May  and  were  still  abroad  as  late  as  August,  appearing  to  increase 
somewhat  as  the  season  advanced. 

PARASITES. 

The  parasitic  species  observed  were  seven  in  number;  the  pre- 
daceous enemies,  six. 

Ophion  tityri  Pack.  (?) — Issued  July  17-August  1. 

Limnerium  sp. — Issued  May  25-30. 

Meteorus  sp. — Issued  July  11-August  2. 

Chelonus  sp. — Issued  July  6,  1908. 

Spiloclialcis  spp. — The  Meteorus  was  attacked  by  two  species  of 
secondary  parasites  of  the  family  Chalcididae.  These  issued  August 
2 from  the  peculiar  brown  cocoons  of  the  Meteorus. 

Winthemia  qucidripustulata  Fab.,  a moderate-sized  tachina  fly,  is 
also  a parasite  on  the  larva  of  this  species.  Adults  issued  August  8 
but  did  not  appear  abundant.  Of  a lot  of  larvae  taken  at  random 
from  different  portions  of  a field,  upward  of  50  per  cent  bore  tachina - 
fly  eggs.  Evidently  a large  percentage  fail  to  hatcli.rt 

aA  small  fly  was  also  observed  feeding  on  tlie  pupse.  It  is  Aphiochceta  nigri- 
ceps  Loew,  one  of  the  Phoridse,  which  comprises  species  of  scavenging  habits 
and  not  parasitic. 

66— v 


64 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


PREDACEOUS  ENEMIES. 

Calosoma  sayi  Dej. — The  larva?  of  the  carabid  beetle  Calosoma 
sayi  were  observed  in  considerable  numbers  and  were  reared  to  adults. 
They  were  first  noticed  July  6,  when  they  were  quite  abundant  in  the 
furrows  between  rows  of  sweet  potato.  They  were  found  concealed 
by  the  vines,  feeding  on  the  larvae  of  the  Prodenia,  and  after  sucking 
out  the  juices  of  one  larva  they  immediately  attacked  another.  The 
adults  issued  in  our  rearing  cages  August  11. 

Polistes  annularis  L. — The  large  brown  wasp  Polistes  annularis 
was  observed  July  2,  flying  quite  commonly  in  sweet-potato  fields. 
One  was  watched  which  alighted  on  a leaf  and  began  searching  for 
prey,  after  the  custom  of  such  wasps.  The  search  was  continued  from 
plant  to  plant  and  from  leaf  to  leaf  until  a Prodenia  larva  was 
located,  when  it  was  at  once  seized  behind  the  head  and  chewed  into  a 
shapeless  mass.  Other  wasps  of  this  species  were  also  seen  on  fence 
posts  dragging  Prodenia  larvae  about  with  them. 

It  is  interesting  to  note  that  Mr.  F.  F.  Crevecoeur,  Onaga,  Kans., 
reports  having  seen  this  wasp  being  carried  away  by  the  asilid 
robber- fly,  Deromyia  ternata  Loew. 

Stiretrus  anchorago  Fab.,  var.  diana  Fab. — The  blue-and-red  and 
the  uniformly  blue  forms  of  the  soldier-bug  Stiretrus  anchorago , 
which  are  common  in  Florida,  were  observed  in  numbers  attacking 
the  Prodenia  larvae  in  July. 

Podisus  maculiventris  Say. — During  July  the  spined  soldier-bug 
was  seen  preying  upon  the  Prodenia  larvae.  (See  fig.  11.)  In  one 
instance  18  nymphs  were  counted  on  a single  amaranth  plant  infested 
by  the  cutworm.  The  length  of  the  life  cycle  of  this  species  from 
hatching  (not  from  egg-laying)  was  determined  to  be  16  days  in  hot 
July  weather. 

Apateticus  ( Eupodisus ) mucronatus  Uhl. — July  17,  and  again  in 
December,  1907,  this  pentatomid  bug  was  observed  preying  on  the 
larva  of  this  species  of  Prodenia  at  Orlando,  Fla.  It  is  considered  a 
rare  species  and  this  is  probably  the  first  observation  which  has  been 
made  on  its  habits. 

Owing  to  the  obscurity  of  the  host  insect  in  the  past,  no  records 
can  be  found  of  any  of  these  parasites  or  of  other  natural  enemies 
which  affect  it,  but  in  Smith  and  Abbot’s  work  mention  is  made  of  a 
species  of  u Ichneumon  ” which  attacks  the  larva  (see  p.  58). 

Pontia  rapce  L. — July  22,  1907,  the  young  larva?  of  the  imported 
cabbage  worm,  which  had  hatched  out  on  cabbage  used  as  food  for 
Prodenia  < ridania  Cram,  in  our  rearing  cages  at  Washington,  were 


THE  SEMI  TROPICAL  ARMY  WORM. 


65 


observed  feeding  on  the  eggs  of  the  latter.®  The  cabbage  worms  were 
between  one-quarter  and  three-eighths  of  an  inch  in  length  at  this 
time. 

A FUNGOUS  DISEASE. 

Empusa  sp. — September  8,  1907,  a few  Prodenia  caterpillars,  which 
were  found  dying  of  a fungous  disease  in  our  rearing  cages,  were 
referred  to  the  Bureau  of  Plant  Industry  for  identification  of  the 
fungus.  Mrs.  F.  W.  Patterson  stated  that  it  was  a species  of  Empusa. 

METHODS  OF  CONTROL. 

The  arsenical  poisons  are  effective  against  this  army  worm  under 
ordinary  conditions.  Experiments  performed  at  Orlando,  Fla.,  how- 
ever, brought  out  the  fact  that  Paris  green,  on  account  of  the  frequent 
rains  which  occur  at  the  height  of  the  principal  outbreaks  in  the 
infested  regions  of  Florida,  such  as  Orlando,  is  almost  ineffective  and 
it  is  therefore  necessary  to  use  arsenate  of  lead.  Owing  to  the 
greater  adhesiveness  of  the  latter  it  remains  on  the  plants  when  the 
former  is  washed  off. 

Paris  green,  arsenate  of  lead,  and  a special  preparation  which  may 
be  called  adhesive  copper  arsenite,  were  tested,  the  last  by  request  of 
its  inventor.  It  was  used  in  experiments  Nos.  8,  10,  and  11.  A barrel 
sprayer,  fitted  with  Yermorel  nozzle,  was  used  for  a number  of  these 
experiments,  but  for  most  of  them  a knapsack  sprayer  of  fine  quality 
was  employed.  Sweet  potatoes  were  sprayed  in  every  case  except  in 
experiment  No.  5,  where  collards  were  also  sprayed,  and  the  work  was 
usually  begun  between  8 and  10  a.  m.  in  bright  sunlight.  Spraying 
experiments  commenced  July  12  and  were  continued  until  August  7. 

Experiment  No.  1. — July  12,  infested  plants  were  sprayed  with  a 
solution  of  Paris  green,  5 ounces,  and  fresh  air-slaked  lime,  5 ounces, 
in  50  gallons  of  water.  The  spraying  was  done  in  the  morning  and 
rain  fell  before  noon.  The  next  day  when  the  field  was  examined 
the  larvse  were  found  uninjured  and  practically  no  poison  remained 
on  the  leaves.  The  experiment  was  therefore  a failure. 

Experiment  No.  %. — July  12,  Paris  green,  8 ounces,  and  freshly 
slaked  lime,  1 pound  to  50  gallons  of  water,  were  sprayed  the  same 
day  and  with  the  same  results. 

Experiment  No.  3. — July  17,  Paris  green  was  sprayed  as  in  No.  2. 
Airain  rain  fell  hard  and  steadily  before  noon,  with  the  same  results 
as  in  experiments  1 and  2. 

a This  would  seem  to  furnish  at  least  one  reason  why  this  important  insect 
lias  been  able  to  supplant  its  American  cousins  such  as  Pontia  napi  L.,  P.  pro- 
todice Bdv.  & Lee.,  and  P.  monuste  L.,  all  of  which  feed  on  crucifers  and  are 
called  cabbage  butterflies  or  “ worms.” 

66 — v 


66 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Experiment  No.  J. — Arsenate  of  lead,  2 pounds  to  50  gallons  of 
water,  was  used.  Rain  fell  as  before,  resulting  in  partial  failure  of 
the  experiment,  the  poison  being  washed  off  before  it  had  time  to 
dry  thoroughly. 

Experiment  No.  5. — July  20,  arsenate  of  lead  was  used  as  in  experi- 
ment No.  4.  Collards  were  also  sprayed.  Rain  did  not  ensue  for  at 
least  six  hours,  giving  the  spray  time  to  dry  on  well  in  the  warm  sun. 
The  following  day  it  rained  hard  for  several  hours,  but  the  next 
day  the  spray  was  found  to  be  as  thick  on  the  sweet  potatoes  as  when 
first  put  on,  in  spite  of  two  partially  rainy  days.  The  poison  was 
nearly  as  thick  on  the  collards.  An  examination  of  the  infested  plants 
two  daA^s  after  spraying  showed  that  only  25  per  cent  of  the  caterpil- 
lars were  killed,  but  July  23,  a day  later,  few  large  larvae  remained 
on  the  plants,  showing  that  as  soon  as  they  have  eaten  sufficient  poison 
they  are  killed. 

July  29,  when  the  rows  sprayed  with  arsenate  of  lead  were  again 
examined,  they  were  found  in  much  better  condition  than  the  check 
or  unspraved  rows,  few  larvae  being  seen  feeding,  while  dead  ones  were 
plentiful. 

Experiments  Nos.  6 and  7. — July  20,  a sweet-potato  patch  was 
sprayed  with  Paris  green,  8 ounces  to  50  gallons  of  water.  As  in  the 
case  of  experiment  5,  no  rain  fell  for  about  six  hours;  therefore  the 
poison  dried  on  well,  as  previous^.  The  following  day  it  rained 
hard  for  several  hours,  with  the  result  that  by  July  22  the  poison 
was  all  washed  off  and  only  a few  dead  larvae  were  found.  All  of 
the  Paris  green  experiments  were  failures,  since  the  rain  washed  the 
poison  off  either  before  it  could  dry  or  after  it  was  well  dried  on  the 
plant. 

Experiment  No.  8. — July  23,  the  adhesive  copper  arsenite  (com- 
bined with  dextrine  and  glucose)  was  used  at  the  rate  of  1 pound  to 
100  gallons  of  water  and  applied  as  in  previous  experiments.  The 
following  day  no  results  were  observed,  but  the  foliage  was  not 
burned.  At  the  end  of  a week  no  good  was  accomplished  and  the  ex- 
periment was  pronounced  a failure. 

Experiment  No.  9. — July  25,  plants  were  again  sprayed  with  ar- 
senate of  lead,  2 pounds  to  50  gallons  of  water,  the  conditions  being 
as  in  experiment  No.  5.  Rain  at  12.45  p.  m.  washed  off  the  poison, 
consequently  the  spraying  was  a failure. 

Experiment  No.  10. — July  25,  plants  were  sprayed  with  the  copper 
arsenite  mixture;  10  ounces  to  50  gallons  of  water  Avere  applied  as  in 
experiment  No.  8,  an  equal  quantity  of  lime  having  been  added.  The 
spray  did  not  show  well  on  the  foliage  and  was  invisible  when  dry. 
It  does  not  remain  in  suspension  as  well  as  Paris  green  and  much 
residue  remains  in  the  tank.  July  28,  a few  dead  larvae  Avere  found 


06 — v 


THE  SEMI  TROPICAL  ARMY  WORM. 


67 


on  the  vines  and  only  a few  live  ones,  but  the  same  conditions  were 
observed  on  the  check  rows.  The  experiment  was  an  absolute  failure. 

Experiment  No.  11. — July  29,  plants  were  sprayed  with  copper 
arsenite  mixture  at  the  rate  of  15  ounces  to  50  gallons  of  water.  In 
this  case  1^  ounces  of  copper  arsenite  and  1 quart  of  thick  lime  were 
used  with  5 gallons  of  water.  Two  days  later  the  spray  showed  better 
than  in  experiment  No.  10  because  of  an  abundance  of  lime  and  was 
very  finely  and  evenly  applied  to  the  leaves.  Four  larvse  were  dead 
on  a few  plants  examined  against  32  living  Prodenia  and  3 living 
sweet-potato  sphinx-moth  larvse  ( PKlegethontius  convolvuli  L.). 

August  6,  this  spray  *still  remained  on  the  foliage,  seeming  to 
adhere  well,  but  the  experiment  was  a failure  in  killing  larvse. 

Experiment  No.  12. — July  29,  plants  were  sprayed  with  arsenate  of 
lead,  3 pounds  to  50  gallons  of  water,  applied  as  in  previous  experi- 
ments with  lead  arsenate.  There  was  no  rain  for  24  hours.  On  a few 
plants  examined  three  days  later  41  dead  larvse  were  found  and  49 
living,  an  observed  death  rate  of  less  than  50  per  cent.  It  should  be 
pointed  out  at  this  time,  however,  that  it  is  difficult  to  find  dead  larvse, 
as  they  sometimes  dry  up  or  crawl  away. 

August  2,  the  vines  were  almost  free  from  larvse.  The  experiment 
was  pronounced  very  successful. 

Experiment  No.  13. — July  30,  arsenate  of  lead,  2 pounds  to  50  gal- 
lons of  water,  was  used  without  ensuing  rain.  In  some  rows  exam- 
ined August  1 about  20  per  cent  of  the  larvse  were  dead ; in  others  48 
per  cent,  54  per  cent,  and  61  per  cent  were  killed  in  two  days.  August 
5,  these  rows  appeared  entirely  free  from  larvse  unless  closely  in- 
spected, when  only  5 or  6 could  be  found  to  a row.  These  might  have 
crawled  from  unsprayed  weeds  or  other  plants. 

Experiment  No.  11+. — July  30,  arsenate  of  lead,  3 pounds  to  50  gal- 
lons of  water,  was  used.  Three  days  later  84  per  cent  of  the  larvse 
under  observation  were  destroyed,  the  rows  being  quite  clean.  In 
both  of  these  experiments,  13  and  14,  many  dead  larvse  were  found  in 
rows  not  sprayed,  as  many  as  five  rows  away  from  the  sprayed  ones. 

Experiment  No.  15. — August  7,  arsenate  of  lead,  2 pounds  to  50 
gallons  of  water,  was  sprayed  by  a laborer,  under  supervision.  It 
rained  at  1 p.  m.,  but  the  spray  remained  on  the  leaves  in  large 
amounts  and,  for  having  been  applied  by  an  inexperienced  hand,  was 
well  distributed.  In  this  experiment,  for  some  reason,  the  first  four 
rows  sprayed  at  one  filling  of  the  tank  produced  quite  a number  of 
burned  leaves.  This  was  attributed  to  a possible  mistake  in  weigh- 
ing out  the  chemicals.  It  did  not,  however,  permanently  injure  the 
plants. 

Caterpillars  in  the  last  4 experiments,  supposedly  of  the  third  gen- 
eration, were  very  small,  not  over  one-fourth  or  one-third  of  an  inch 
in  length.  As  a consequence  they  were  quickly  killed,  large  numbers 

66 — v 


68 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CHOPS. 


of  them  being  found  dead  soon  after  spraying.  Forty-three  dead 
larvae  were  found  in  a furrow  beside  one  plant  which  contained  29 
dead  larvae.  In  another  place  112  dead  larvae  were  counted  in  3 
feet  of  furrow. 

RESUME  OF  EXPERIMENTS,  AND  CONCLUSIONS. 

Experiments  1,  2,  3,  C,  and  7.  in  which  Paris  green  was  used  at  the 
rate  of  5 to  8 ounces  in  0 gallons  of  water,  were  failures  because  in 
each  case  the  rain  which  followed  the  application  washed  off  the 

1 Experiments  1 and  9,  in  which  arsenate  of  lead  was  used  at  the  rate 
of  2 pounds  to  50  gallons  of  water,  were  also  failures  for  the  same 

reason.  -,  , 

Experiments  8,  10,  and  11,  in  which  copper  arsemte  was  used  at 

a rate  of  from  10  ounces  to  1 pound  in  50  gallons  of  water,  failed, 
not  because  of  burning  the  foliage,  as  was  feared,  but  because  the  in- 
sects were  not  killed.  , 

Experiments  5,  12,  18,  Id,  and  15,  in  which  arsenate  of  lead  was  the 

insecticide  employed  at  the  rate  of  2 to  3 pounds  in  50  gallons  of 

water,  were  successful  in  each  case.  . 

The  results  of  this  series  of  fifteen  experiments  show  conclusively 
the  superiority  of  a spray  of  arsenate  of  lead  to  one  of  Pans  green 
when  applied  under  suitable  conditions.  It  is  m every  way  more 
effective  and  more  satisfactory  than  the  latter,  as  Pans  green  is  so 
likely  to  be  washed  away  by  the  frequent  rains  of  the  wet  season  ot 
Florida.  These  remarks  apply  practically  to  all  cutworms,  cater- 
pillars, and  other  larva;  which  devour  truck  and  related  crops  in 
central  Florida  or  similar  regions. 

ADHESIVE  COPPER  ARSEN1TE  MIXTURE. 

The  preparation  of  copper  arsenite  used  in  the  experiments  that 
have  just  been  reported  was  stated  by  its  inventor  to  be  free  from 
soluble  arsenious  acid  and  to  possess  the  adhesive  properties  found  in 
no  other  adhesive  insecticide.  It  was  stated  to  be  composed  of  36 
per  cent  dextrin  and  4 per  cent  gum  and  was  prepared  to  be  used  m 
conjunction  with  lime  in  the  proportion  of  1 part  by  weight  to  from  4 
to  C parts  of  lime — either  dry  or  in  solution,  according  to  the  fohage 
to  be  tested.  The  inventor  also  expressed  his  confidence  that  this 
insecticide  would  prove  a most  economical  one  for  genera  gardep 
and  other  use,  as  the  loss  by  wind  and  rain  would  be  reduced  at  leas 
50  per  cent  and  the  first  cost  of  the  article  would  be  about  half  that 

of  Paris  green  or  arsenate  of  lead.  T T_  TT  , 

Samples  of  this  mixture  were  submitted  to  Mr.  J.  K.  Haywood 
Chief  of  the  Miscellaneous  Laboratory,  Bureau  of  Chemistry,  who 
furnished  the  following  analysis.  August  i,  190i  : 


THE  SE  MIT  R OPT  CAL  ARMY  WORM. 


69 


Analysis  of  4 551  Misc. 

Per  cent. 


Moisture v 4.  85 

Total  arsenious  oxid 40.42 

Total  copper  oxid 24.87 

Gum  and  dextrin  (approximate) ......  ___  20.00 

Acetic  acid  and  other  undetermined--.  9.86 


Total 100.00 

Soluble  arsenious  oxid 11.36 

(10  day  water  ext.  method.) 


From  the  above  analysis  the  sample  evidently  consists  of  about  20  per  cent 
gum  and  dextrin  and  80  per  cent  Paris  green.  The  amount  of  soluble  arsenic  is 
very  high  and  would  undoubtedly  give  rise  to  serious  trouble. 


SUMMARY. 

The  semitropical  army  worm  is  a smooth  or  hairless  noctuid 
caterpillar,  Prodenici  eridania  Cram.  It  feeds  normally  on  weeds, 
such  as  the  poke  weed  and  spiny  amaranth  or  “ careless  weed  ” of  the 
South,  and  is  confined  to  semitropical  America  as  a pest.  When  it 
becomes  unduly  abundant  it  attacks  the  foliage  and,  in  some  cases, 
the  stems  and  fruits  of  all  forms  of  garden  truck  growing  in  its 
habitat,  the  list  of  known  food  plants  including  tomato,  potato,  sweet 
potato,  eggplant,  pepper,  okra,  collards,  and  cowpeas.  In  its  habits 
it  is  similar  to  the  cutworms,  having  also  the  climbing  habit,  and 
when  extremely  abundant  it  migrates  in  armies  like  the  common  army 
worm,  whence  the  name. 

Experiments  show  that  the  egg  period  may  be  passed  in  a min- 
imum of  4 days,  the  larval  period  in  IT  days,  and  that  the  entire  life 
cycle,  in  an  outdoor  summer  temperature,  would  be  about  35  days  or 
5 weeks;  also,  that  there  are  four  generations  and  possibly  five  pro- 
duced  in  a year,  the  insect  breeding  practically  continuously  during 
the  warm  season.  In  ordinary  }Tears  the  species  is  largely  controlled 
by  natural  enemies,  of  which  seven  are  parasitic  and  six  predaceous. 

A series  of  fifteen  experiments  was  conducted  against  this  species 
in  Florida  during  1907,  which  shows  conclusively  that  a spray  of 
arsenate  of  lead  is  the  best  remedy,  being  much  superior  to  Paris 
green  when  applied  under  local  conditions.  Tt  is  in  every  way  more 
effective,  chiefly  because  less  likely  to  be  washed  awa}^  by  the  frequent 
rains  of  the  wet  season  in  that  region.  It  is  best  applied  at  the  rate 
of  2 or  3 pounds  in  50  gallons  of  water,  and  applications  must  be 
renewed  when  the  insects  again  become  numerous,  as  the  latter  are 
apt  to  spread  from  unsprayed  plants. 

66 — v 


70 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


BIBLIOGRAPHICAL  LIST. 

1.  Cramer,  Pierre. — Papillons  exotique,  Vols.  Ill  & IV,  p.  133,  pi.  358,  fig. 

E.  & F.  (2),  1782. 

Description  and  figures  of  both  varieties  of  moths. 

2.  Smith,  J.  E.  and  Abbot,  M.  J. — Lepidopterous  insects  of  Georgia,  Vol.  II, 

p.  193,  pi.  97,  1797. 

Described  as  Phalcena  phytolaccce  with  brief  account  of  habits.  Figures  of  moth 
and  larva. 

3.  Grote,  A.  R. — Bui.  Buff.  Soc.  Nat.  Sci.,  Vol.  II,  p.  28,  1873. 

Listed  as  Xylomiges  phytolaccce  (S.  & A.)  and  recorded  from  California  and 
Atlantic  District. 

4.  Morrison,  H.  K. — Proc.  Acad.  Nat.  Sci.  Phila.,  p.  62,  1875. 

Technical  description  as  Actinotia  dervpta  n.  sp.,  from  Texas,  September  21. 
Briefly  compared  with  phytolaccce  S.  & A. 

5.  Grote,  A.  R. — Can.  Ent,  Vol.  XI,  pp.  205,  206,  1879. 

Received  from  Texas  and  referred  to  Prodenia  phytolaccce ; characters,  etc. 
No  excuse  for  Morrison’s  Actinotia  derupta. 

6.  Hulst,  G.  D.— Bui.  Brooklyn  Ent.  Soc.,  Vol.  Ill,  p.  77;  Vol.  IV,  p.  7,  pi.  1, 

fig.  9,  1881. 

Described  as  Leucania  nigrofascia  from  one  specimen  taken  by  Koebele  at 
Tallahassee,  Fla. 

7.  Smith,  J.  B. — Catalogue  Noctuidse  Boreal  America,  p.  169,  1893. 

Bibliography  ; synonymy  and  distribution. 

8.  [Chittenden,  F.  H.]— Yearbook  U.  S.  Dept.  Agr.,  1907  (1908),  p.  545. 

Brief  unsigned  notice  of  injury  to  truck  crops  in  Florida. 

In  Smith’s  catalogue  of  Noctuidse,7  fifteen  references  are  given  to 
this  species,  but  as  only  a few  of  these  are  of  interest  in  connection 
with  the  present  account,  the  reader  is  referred  to  that  list.  The  more 
important  references  are  listed  above. 

66 — v 


O 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY— BULLETIN  No.  66,  Part  VI. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  HOP  FLEA-BEETLE. 


F.  H.  CHITTENDEN,  Sc.  D., 


In  Charge  of  Truck  Crop  and  Special  Insect  Investigations . 


Issued  May  8,  1909. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1909. 


CONTENTS. 


Page. 

Introductory 71 

Descriptive 72 

Distribution 73 

Recent  injuries 73 

Methods  of  attack,  food  habits,  and  generations 76 

Life  history  and  habits 79 

Notes  on  other  species 81 

Local  conditions  and  natural  influences 82 

M ethods  of  control 83 

Arsenicals 83 

Arsenate  of  lead 83 

Dry  Paris  green 84 

Paris  green  spray 84 

Other  arsenicals 85 

Summary  on  the  use  of  arsenicals * 85 

Contact  sprays 85 

Bordeaux  mixture 87 

Mechanical  and  cultural  methods 87 

Trap  crops 87 

Rolling  the  fields 87 

The  use  of  fertilizers 88 

Irrigation 88 

Tarred  catchers 88 

Clean  cultivation 89 

Literature 91 

Bibliography 91 

Summary 92 

66— vi 


in 


ILLUSTRATIONS. 


PLATES. 

Page. 

Plate  Y.  Spraying  apparatus  used  in  hopyards  in  British  Columbia 84 

VI.  View  of  hopyard  showing  sheep  keeping  down  weeds 88 

VII.  Method  of  capturing  hop  flea-beetles  on  tarred  horse-sledges 90 

TEXT  FIGURES. 

Fig.  12.  Hop  flea-beetle  (Psylliodes  punctulata):  Larva  and  adult 72 

13.  View  of  hopyard,  showing  how  flea-beetles  keep  down  vines 76 

14.  Hop  leaves,  showing  work  of  flea- beetle 77 

15.  Work  of  flea-beetle  after  vines  are  grown 78 

16.  Trained  hop  shoots  stripped  by  flea-beetle 79 

17.  Breeding  and  control  cage  in  place  over  a hill 80 

18.  A crew  spraying  hops  in  British  Columbia 86 

19.  Tarred  catchers  for  hop  flea- beetles 89 

66— vi 


IV 


U.  S.  D.  A.,  B.  E.  Bui.  66,  Tart  VI. 


Issued  May  8,  1909. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


THE  HOP  FLEA-BEETLE. 

( Psylliodes  punctulata  Melsh.) 

By  F.  H.  Chittenden,  Sc.  D., 

In  Charge  of  Truck  Crop  and  Special  Insect  Investigations. 

INTRODUCTORY. 

A minute,  metallic  blackish  flea-beetle, Psylliodes  punctulata  Melsh., 
known  by  different  local  names,  has  been  reported  in  recent  years  as 
doing  very  extensive  injury  to  the  hop  plant  and  considerable  injury 
to  sugar  beet.  Since  1904  it  has  been  reported  in  numbers  on  sugar 
beets  grown  in  several  localities  in  Idaho,  Utah,  and  Colorado.  In 
the  Northwest,  and  particularly  in  British  Columbia,  it  does  serious 
damage  in  liopyards,  and  has  been  especially  destructive  since  1903. 
During  the  past  three  years,  indeed,  this  species  has  become  unusually 
abundant,  with  the  result  that  in  the  Chilliwack  and  Agassiz  Valley 
hop-growing  regions  of  British  Columbia  it  has  accomplished  damage 
which  has  been  estimated  by  Mr.  H.  J.  Quayle  as  about  80  per  cent 
of  the  crop.  Mr.  Theo.  Eder  informs  the  writer  that  this  means  a 
cash  loss  of  not  less  than  $125,000  in  that  district.  The  species  during 
that  period  has  been  the  subject  of  considerable  correspondence  be- 
tween this  Department  and  persons  practically  interested  in  the  grow- 
ing of  hops  in  the  affected  region. 

The  insect  has  received  the  name  of  rhubarb  flea-beetle,  from  its 
common  occurrence,  especially  in  the  East,  on  rhubarb.  In  the  West 
it  is  called  the  hop  flea-beetle,  or  “ hop  flea,”  or  simply  “ flea,”  and  in 
literature  it  has  received  mention  as  the  punciulated  and  the  small- 
punctured  flea-beetle. 

While  the  species  is  not  known  to  be  of  the  highest  importance  as  a 
sugar-beet  pest,  the  probabilities  are  that  it  may  become  so,  and  at  the 
present  time  it  is  probably  the  most  important  hop  pest  in  the  entire 
world.  The  incorporation  of  some  new'  matter,  gained  from  con- 
versation with  Mr.  Theo.  Eder  and  by  correspondence  with  Mr.  H.  J. 

66 — vi  71 


72 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS, 


Quayle,  has  added  much  to  the  value  of  the  present  paper.  Although 
the  species  is  much  more  serious  as  a pest  in  British  Columbia  than 
in  the  United  States,  it  is  likely  to  become  important  throughout 
the  Pacific  coast  region  where  hops  are  grown.  Mr.  Eder  repre- 
sents the  E.  Clemens  Horst  Company,  which  owns  extensive  hop- 
yards  in  British  Columbia,  and  has  already  expended  considerable 
sums  in  investigation  and  experiments.  The  hop  flea -beetle  is  now 
abundant  practically  on  the  border  line  between  British  Columbia 
and  the  State  of  Washington,  and  threatens  our  own  industries.  It  is, 
therefore,  advisable  that  everything  possible  concerning  it  should  be 
made  public  before  its  appearance  in  the  spring,  although  there  are 
several  points  in  its  life  history  still  to  be  worked  up. 


The  hop  flea-beetle  (fig.  12)  is  a member  of  the  tribe  Halticini, 
family  Chrysomelidae,  and  resembles  other  flea-beetles  in  its  strongly 


Fig.  12. — The  hop  flea-beetle  ( Psylliodes  punctulata)  : a.  Larva;  b,  lower  surface  of  head 
of  same ; c , upper  surface  of  anal  segments  of  same ; d,  beetle,  a,  d , Much  enlarged ; 
6,  c,  more  enlarged.  ( a-c , After  Carpenter;  d,  original.) 


developed  hind  thighs.  It  is  of  oval  form,  with  a greenish  tinge, 
brassy  blackish,  and  punctulate  or  finely  punctured,  whence  its  spe- 
cific name.  The  femora,  tarsi,  and  basal  joints  of  the  antenna*  are 
pale  yellowish.  The  punctulations  of  the  thorax  are  particularly 
fine  and  appear  as  if  made  with  the  point  of  a very  fine  needle.  The 
punctures  of  the  elytral  striae  are  closely  placed,  almost  crenate.  The 
beetle  is  only  about  one-tenth  of  an  inch  (2mm)  in  length  and 
less  than  lmm  in  width.  The  male  is  particularly  distinctive,  hav- 
ing the  first  joint  of  the  anterior  tarsi  broadly  dilated  and  the  last 


DESCRIPTIVE. 


66— vi 


THE  HOP  FLEA-BEETLE. 


73 


ventral  segment  sinuate  each  side,  while  the  middle  of  the  disk  near 
the  apex  has  a semioval  depression.® 

The  species  was  first  described  in  1847.1  6 

DISTRIBUTION. 

The  hop  flea-beetle  is  a native  American  species,  quite  distinct  from 
any  species  found  on  hops  in  England  or  on  the  Continent. 

The  collection  of  the  U.  S.  National  Museum  and  the  published 
records  and  specimens  before  the  writer  show  the  species  to  be  gen- 
erally distributed  in  the  northern  United  States  and  southern  Canada, 
from  the  Atlantic  to  the  Pacific.  It  does  not  appear  to  occur  south 
of  Nebraska.  The  list  of  known  localities  follows : Cambridge,  Mass. ; 
Dundee,  Ithaca,  Long  Island,  Staten  Island,  and  New  York,  N.  Y. ; 
New  Jersey,  generally  distributed  (Smith)  ; Pittsburg,  Pa.;  Marshall 
HalJ  and  Cabin  John,  Md. ; Marquette,  Detroit,  Grand  Ledge,  and 
Byron,  Mich. ; University,  N.  Dak. ; Lincoln  and  Omaha,  Nebr. ; Fair- 
field,  Wyo. ; Denver,  Longmont,  Grand  Junction,  Delta,  Montrose, 
Paonia,  and  Ft.  Collins,  Colo.;  Logan,  Garland,  Lehi,  Salt  Lake,  and 
Park  City,  Utah;  Elko,  Nev. ; Blackfoot,  Idaho;  San  Francisco,  Mar- 
tinez, Monterey,  Huntington  Beach,  Pasadena,  and  Chico,  Cal. ; 
Tenino,  Wash.;  Astoria  and  Marion,  Oreg. ; Agassiz,  Sardis,  and 
Vancouver,  British  Columbia;  Northwest  Territory;  Manitoba;  and 
“ Assiniboia  ” (now  Saskatchewan). 

RECENT  INJURIES. 

September  16,  1903,  the  late  Dr.  James  Fletcher  first  reported  this 
species  injuring  hops  in  British  Columbia. 

During  1906  Mr.  Theo.  Eder  wrote  from  San  Francisco,  Cal.,  under 
date  of  April  9,  that  hop  growers  were  troubled  considerably  in  some 
sections  by  u hop  fleas,”  or  flea-beetles.  May  29,  specimens  were 
received  from  Perkins,  near  Sacramento,  Cal.,  which  proved  to  be 
the  species  under  consideration.  August  13,  Mr.  Hugh  F.  Fox,  New 
York,  N.  Y.,  sent  specimens  and  transmitted  a report  from  Mr.  Geo. 
Heggie,  manager  of  a large  hopyard,  the  Stepney  ranch,  owned  by 
Sir  Arthur  Stepney,  at  Enderby,  B.  C.,  where  this  pest  was  very 
injurious.  Mr.  Heggie  wrote  as  follows : 

We  have  been  sorely  troubled  this  year  in  our  hopyard  with  the  “ hop  flea- 
beetle,”  which  attacks  the  young  vine  and  leaf  as  soon  as  they  appear  above 
the  ground,  and  eats  out  large  holes  in  the  leaf,  resulting  in  the  plant  being 

a In  the  very  closely  related  Ps.  convexior  Lee.  the  last  ventral  segment  of  the 
male  is  convex  and  not  impressed.  The  latter  species  is,  moreover,  larger, 
broader,  and  more  convex,  and  the  elytral  striae  are  not  impressed. 

6 The  numbers  in  superior  type  refer  to  corresponding  numbers  in  the  ap- 
pended bibliography,  p.  91. 

66 — vi 


74 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


impoverished  in  vitality  and  the  growth  thereby  seriously  retarded.  We  were 
troubled  with  them  last  year  [1905],  but  not  to  the  same  extent,  and  had  them 
till  after  hop  picking.  In  the  middle  of  July  they  were  so  numerous  that  the 
ground  was  fairly  alive  with  them.  They  go  into  the  ground  in  the  evening 
and  come  out  again  in  the  morning,  and  there  has  been  no  spray  found  to  have 
any  effect  without  killing  the  plant. 

Substantially  the  same  form  of  injury  was  reported  during  the 
same  year  at  Agassiz,  B.  C.,  by  Mr.  John  Wilson  in  a letter  to  Doctor 
Fletcher.  Writing  September  7,  1906,  Doctor  Fletcher  stated  that 
this  species  had  been  enormously  destructive  in  British  Columbia, 
one  correspondent  reporting  the  loss  of  many  thousands  of  dollars. 
He  estimated  his  crop  as  possibly  70  bales,  whereas  he  should  have 
had  250. 

Writing  of  this  species,  January  30,  1907,  Dr.  E.  D.  Ball,  while 
working  in  cooperation  with  the  writer,  stated  that  it  was  by  far  the 
most  injurious  species  on  sugar  beet  in  Utah.  It  was  found  every- 
where and  was  apparently  the  most  common  species  in  early  spring. 
It  was  observed  hibernating  around  the  edges  of  fields,  in  patches  of 
dead  mustard,  along  ditch  banks,  and  in  similar  places.  Where 
ditches  were  covered  with  patches  of  roses  these  seemed  to  furnish  a 
favorite  retreat.  These  clumps  grew  to  a height  of  2 or  3 feet  and 
were  very  dense,  and  from  them  one  could  see  the  injury  to  the  beets 
radiating  in  every  direction,  the  affected  area  growing  wider  and 
wider  as  time  went  on.  In  early  spring  this  species  fed  on-  almost 
anything  that  came  to  hand,  but  its  injury  to  beets  was  practically 
all  done  at  the  time  the  plants  were  first  appearing  through  the 
ground  or  within  a few  days  thereafter.  Cases  were  observed  where 
the  rows  of  young  plants  could  be  seen  the  entire  length  of  the  field 
one  day,  and  two  days  later  scarcely  a beet  plant  could  be  found,  the 
beetles  having  eaten  the  tender  stem,  causing  the  tops  to  fall  off  and 
the  beets  to  die.  Frequently  they  attacked  beets  just  as  the  latter 
were  pushing  through  the  ground.  Hundreds  of  acres  had  been 
destroyed  in  this  way,  injury  varying  greatly  in  different  years  and 
in  different  localities. 

Great  damage  was  done  near  Logan,  Utah,  where  the  hedge  mus- 
tard was  overrunning  the  fields.  At  Lewiston,  Utah,  at  the  northern 
end  of  the  same  valley,  injury  was  also  severe,  although  there  was 
little  of  the  common  black  mustard. 

The  destruction  of  a crop  by  this  species  does  not  necessarily  entail 
a complete  loss,  as  the  growers  replant.  The  late  plants,  however, 
are  not,  as  a rule,  as  good  as  the  earlier  ones,  and  the  weeds  get  such  a 
start  that  the  land  is  hard  to  cultivate.  After  the  beets  had  reached 
a leaf  diameter  of  3 or  4 inches  no  material  injury  was  noticed, 
although  the  beetles  continued  to  appear  in  the  fields  throughout  the 
season.  Beetles  were  observed  July  20,  1906,  at  Cache  Junction, 

66— vi 


THE  HOP  FLEA-BEETLE. 


75 


Utah,  enormously  abundant  on  a form  of  hedge  mustard  along  the 
railroad  tracks,  feeding  on  the  half-grown  seeds.  Single  plants  were 
seen  on  which  a double  handful  of  beetles  could  be  taken  at  one  stroke 
of  the  net. 

In  a letter  dated  July  20,  1908,  the  E.  Clemens  Horst  Company, 
Perkins,  Cal.,  wrote  of  extensive  injury  by  this  species,  and  as  this 
letter  contains  much  of  interest  it  is  transcribed  herewith.  The 
writer  is  greatly  indebted  to  the  same  company  for  the  excellent  pho- 
tographs from  which  the  ten  half-tones  illustrating  this  article  are 
taken. 

We  are  extensive  growers  of  hops  on  the  Pacific  Slope,  California  and  Oregon, 
and  also  have  about  600  acres  of  hops  in  two  ranches  in  British  Columbia. 
For  the  past  three  years  we  have  been  very  much  molested  in  British  Columbia 
by  a variety  of  flea-beetle  that  seems  to  take  an  especial  liking  to  hop  foliage 
and  eats  the  young,  tender  shoots  as  they  come  out  of  the  ground,  and  also  the 
developed  and  partly  developed  leaves  of  the  vines  after  the  same  are  above 
ground.  There  are  two  other  growers  in  the  same  section  that  were  bothered 
one  or  two  years  previous  to  ourselves,  and  as  they  had  some  foreign  varieties 
of  hops  we  at  first  supposed  the  insects  had  been  imported  from  England  in  the 
roots.  Since,  however,  we  have  found  that  the  same  insect  has  been  in  the 
neighborhood  in  very  small  numbers  for  quite  a long  term  of  years.  Our  crops 
in  British  Columbia  suffered  quite  a bit  last  season,  but  this  year  are  very 
nearly  a total  failure.  From  the  one  place,  Chilliwack,  B.  C.,  containing  278 
acres,  we  do  not  expect  to  reap  a harvest  of  more  than  600  bales,  whereas  we 
should  have  from  2,500  to  3,000  bales.  From  the  other  place,  Agassiz,  B.  C., 
we  do  not  expect  over  250  bales  of  hops,  whereas  we  should  have  2,250  to  2,700 
bales.  This  will  give  you  some  idea  of  the  inroads  made  by  the  insect  and  the 
resultant  loss  to  persons  engaged  in  hop  growing  when  their  yards  are  attacked 
by  these  pests.  Of  course  we  readily  understand  that  it  would  be  somewhat  out 
of  the  ordinary  for  your  Department  to  attack  this  problem  inasmuch  as  it  is 
out  of  the  United  States,  but  inasmuch  as  the  pests  are  now  so  numerous 
within  about  20  miles  of  the  United  States  boundary  and  only  a short  distance 
from  the  Washington  State  hopyards  we  believe  it  is  well  worth  your  considera- 
tion. Just  imagine  for  a moment  the  loss  that  would  fall  to  the  numerous 
growers  of  hops  in  the  States  of  Washington,  Oregon,  or  California,  if  this 
pest  should  not  be  held  in  check,  and  would  migrate  to  these  sections.  We  have 
definite  knowledge  of  their  already  having  spread  as  far  as  Sumas  Junction, 
which  is  on  the  boundary  line  between  the  United  States  and  Canada,  where 
they  are  attacking  cabbage,  potato,  beets,  and  other  root  crops,  though  the 
damage  done  here  is  not  nearly  as  bad  as  in  the  hop  fields.  * * * 

A badly  damaged  hopyard  is  shown  in  figure  13. 

During  1908  injury  from  the  hop  flea-beetle  was  reported  by  Mr. 
W.  W.  Stockberger,  of  the  Bureau  of  Plant  Industry  of  this  Depart- 
ment. He  mentioned  the  cases  already  cited  and  one  reported  by 
Mr.  Bobert  Maitland,  of  Agassiz,  B.  C.,  the  latter  stating  that  the 
ravages  of  this  insect  would  almost  destroy  the  prospect  for  a crop 
during  the  season.  Mr.  John  Wilson,  Agassiz,  B.  C.,  who  complained 
76453— Bui.  66,  pt  6—09 2 


76  SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 

of  this  species  in  earlier  years,  reported,  under  date  of  July  11,  as 
follows : 

The  flea-beetles  have  been  so  numerous  that  they  have  stripped  every  portion 
of  the  yard  this  season.  I have  noticed  these  last  three  days  that  they  are  all 
disappearing,  but  they  all  disappeared  last  season  about  this  time  and  a second 
brood  came  about  the  middle  of  July. 

This  “ second  brood  ” was  probably  merely  the  first-developed  gen- 
eration of  the  year. 

This  species  has  also  come  under  the  observation  of  various  other 
collectors  and  observers.  During  1906  Mr.  Frederick  Maskew,  while 
working  under  the  writer’s  direction  in  southern  California,  took 
it  generally  in  many  beet  fields.  Mr.  E.  G.  Titus,  while  cooperating 


Fig.  13. — View  of  hopyard,  showing  how  completely  the  hop  flea-beetle  keeps  down  the  vines. 
Note  occasional  vine  that  grows  up.  Agassiz,  B.  C.,  June  24,  1908.  (Original.) 


with  this  Bureau  in  the  investigation  of  sugar-beet  pests,  found  it 
abundantly,  and  many  of  the  locality  records  given  under  the  head- 
ing “ distribution,”  in  California,  Utah,  Idaho,  and  other  States  are 
from  specimens  collected  by  him  on  sugar  beet  in  1905,  190T,  and  1908. 

Writing  of  this  species  in  July,  1908,  Mr.  I.  J.  Condit  stated  that 
the  beetles  were  then  very  common  in  the  vicinity  of  Chino,  Cal.,  on 
Chenopodium  album  and  G . rurale. 

METHODS  OF  ATTACK,  FOOD  HABITS,  AND  GENERATIONS, 

This  flea-beetle  affects  both  surfaces  of  a leaf,  gnawing  through 
the  skin  and  devouring  the  pulp,  usually  leaving  the  skin  on  the  op- 
posite side  entire;  this  later  becomes  discolored,  forming  yellowish- 

60 — vi 


THE  HOP  FLEA-BEETLE. 


77 


brown  freckles  as  the  leaf  grows  and  expands,  the  skin  at  this  point 
in  time  becoming  torn  and  frequently  showing  holes.  When  the 
beetle  occurs  in  moderate  numbers  the  leaves  (fig.  14)  become  riddled, 
as  by  fine  shot,  the  punctures  being  most  obvious  after  the  plants  have 
made  some  growth.  In  its  attack  on  hops  it  frequently  causes  the 
leaves  to  look  like  a mass  of  network  or  more  or  less  completely 
strips  the  vines  of  leaves,  as  shown  in  figures  15  and  16.  As  is  the 
case  with  flea-beetles  in  general,  this  species  does  most  harm  to  young 
plants.  When  the  beetles  occur  in  considerable  numbers  they  are 
capable  of  doing  great  damage  in  a comparatively  short  time,  com- 
pletely devouring 
the  young  and 
tender  leaves  as 
fast  as  they  come 
up. 

Injury  is  most 
noticeable  on 
hops,  sugar  beet, 
rhubarb,  and  some 
other  vegetables. 

The  beetle  is  a 
general  feeder,  the 
list  of  its  food 
plants  including, 
among  vegetables, 
rhubarb,  beet,  cu- 
cumber,  turnip, 
radish,  cabbage, 
mustard,  and  po- 
tato. It  feeds  also 

. it  Fig.  14. — Hop  leaves,  showing  work  of  flea-beetlel  (Original.) 

on  hops,  red  and 

white  clover,  nettle,  dock  (Eumex) , lamb’s-quarters  (Chenopodium) , 
pigweed  and  tumbleweed  ( Amaranthus  retroflexus  and  A.  grcecians) , 
hedge  mustard,  and  common  wild-growing  black  mustard.  The  prob- 
abilities are  that,  as  all  of  these  plants  are  affected  by  the  adult  beetles, 
a considerable  proportion  of  them  serves  as  food  for  the  larvae.  On 
this  head  Mr.  Quayle  has  written  that  the  eggs,  larvae,  and  pupae 
were  taken  at  a depth  of  from  three  to  six  inches  from  the  surface 
of  the  ground  in  hop  fields  and  that  the  larvae  apparently  feed  on  the 
roots  of  hop  as  well  as  those  of  other  plants  growing  in  the  yards. 
Since  it  is  well  known  that  the  beetles  occur  in  other  regions  where 
hops  do  not  grow  there  must  be  other  larval  food  plants.  It  would 
be  interesting,  and  is  important,  to  ascertain  exactly  what  plant,  or 
plants,  is  the  favorite  with  the  larvae. 

66— vi 


78 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


Fletcher,11  in  writing  of  this  species,  says  that  in  Canada  there  are 
two  generations  a year,  the  first  appearing  in  J une  and  the  second  in 
August.  The  generation  appearing  in  August  is  with  little  doubt  the 
newly  developed  first  generation,  and,  reasoning  from  analogy,  i.  e., 
from  what  we  know  of  related  flea-beetles,  it  is  this  generation  of  the 
beetle  that  hibernates ; thus  the  so-called  “ first  generation  ” is  simply 

that  same  generation  reappear- 
ing the  following  spring  and 
early  summer 

As  to  hibernation,  Piper 6 
and  Doane 8 have  recorded  that 
the  beetle  passes  the  winter 
under  stones  or  rubbish,  in 
which  respect  it  resembles 
practically  all  other  species  of 
American  flea-beetles,  and  that 
with  the  first  warm  days  of 
spring  the  beetles  emerge  from 
their  winter  quarters  and  im- 
mediately commence  feeding 
voraciously  upon  their  various 
food  plants. 

The  following  account  of 
the  life  history  and  habits  of 
the  species  in  the  worst  affect- 
ed locality  in  British  Colum- 
bia has  been  kindly  furnished 
by  Mr.  H.  J.  Quayle,  who  has 
also  given  an  account  of  reme- 
dial experiments  which  sup- 
plement those  previously  fur- 
nished by  conversation  with 
Mr.  Eder ; indeed,  without  the 
information  supplied  by  these 
two  gentlemen  this  article 
would  be  quite  incomplete. 
Before  transcribing  Mr. 
Quayle’s  account  it  may  be  well  to  draw  from  it,  according  to  the 
statement  of  Mr.  H.  Hulbert,  Sardis,  B.  C.,  that  this  species  made 
its  first  appearance  as  a hop  pest  in  British  Columbia  in  1894  and  that 
it  has  been  of  great  importance  for  five  years,  or  since  about  1903.  In 
regard  to  Mr.  Hulbert ’s  statement  that  the  beetles  disappear  about 
June  1 and  reappear  the  last  of  July,  it  is  obvious  that  during  that 
period  the  larva?  are  maturing,  the  pupa?  are  formed,  and  the  beetles 
of  the  first,  or  new,  generation  appear. 

66— VI 


Fig.  15. — Work  of  flea-beetle  after  vines  are 
grown.  (Original.) 


THE  HOP  FLEA-BEETLE. 


79 


The  following  account  of  the  life  history  and  habits  of  this  species 
as  it  occurs  in  British  Columbia  is  taken  from  Mr.  Quayle’s  manu- 
scripts : 

LIFE  HISTORY  AND  HABITS. 

The  adult. — Tlie  beetle  appears  very  early  in  the  spring  and,  according  to 
reports,  patiently  awaits  the  coming  of  its  food  plant.  This  early  attack  of 
the  beetle  as  the  plants  are  bursting  through  the  ground  and  before  the  leaves 
are  fully  expanded  is  one  of  the  things  that  makes  control  work  difficult. 
Before  the  hops  appear  the  beetles  are 
known  to  attack  the  nettle,  and  often  com- 
pletely riddle  the  leaves.  They  also  attack 
other  plants,  and  have  been  seen,  and  evi- 
dence of  their  work  noticed,  on  potato, 
mangel,  beet,  turnip,  dock,  lamb’s-quarters, 
pigweed,  and  red  as  well  as  white  clover. 

None  of  these  plants  is  attacked,  however, 
in  preference  to  hops  and  it  is  rarely  that 
they  are  found  at  this  season  on  anything 
but  hop  vines.  In  one  or  two  cases  they 
were  observed  in  some  numbers  on  potato, 
at  a considerable  distance  from  hop  vines. 

On  a small  field  of  hops  that  was  deserted 
last  year  on  account  of  this  flea-beetle  and 
planted  to  clover,  the  leaves  of  the  latter 
were  considerably  eaten. 

The  first  appearance  of  the  beetles  in  this 
section,  according  to  Mr.  Hulbert,  was 
fourteen  years  ago,  and  they  have  been 
attacking  his  hops  for  the  past  five  years. 

The  beetles  jump  very  readily  when  dis- 
turbed, but  fall  to  the  ground,  usually  not 
far  from  the  base  of  the  vine.  Experiments 
to  determine  the  power  of  jumping,  which  is 
an  important  factor  in  control  work,  indicate 
that  they  may  not  jump  more  than  a foot 
in  the  vertical  and  about  a foot  and  a half 
in  the  horizontal. 

Feeding  occurs  almost  entirely  on  the 
upper  surface  of  the  leaves,  where  they 
eat  out  small,  nearly  round  holes  about 
one-eighth  of  an  inch  in  diameter.  This  is 
continued  until  the  leaf  is  reduced  to  a network  and  finally  nothing  but  the 
main  ribs  remain.  Many  of  the  vines  grew  to  a height  of  three  or  four  feet, 
then  the  foliage  was  completely  stripped  off,  leaving  the  dead  stalks,  which 
may  still  be  seen  in  the  fields.  Many  of  the  vines  are  thus  killed  to  the 
ground.  Strings  were  put  in  place  in  1908  in  anticipation  of  the  usual  crop, 
but  were  taken  down  and  saved  for  another  year,  as  the  vines  that  started 
afterward  were  too  late  to  make  a crop.  Cultivation  was  stopped  and  a 
thousand  sheep  were  imported  from  California  by  the  Horst  Company  to 
feed  in  their  yards. 

The  beetles,  with  their  more  or  less  cone-shaped  bodies,  readily  make  their 
way  through  anything  into  which  they  can  get  their  heads,  and  our  experi- 
66— vi 


80 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


mental  cages  [fig.  17],  which  were  covered  with  cheese  cloth,  had  to  be  re- 
covered with  calico.  They  also  make  their  way  through  the  soil  with  little 
difficulty.  Experiments  to  determine  this  point  consisted  in  burying  them  at 
different  depths,  enclosed  in  tin  cylinders.  In  two  days  the  beetles  appeared 
through  2,  4,  and  6 inches  of  loose  soil,  but  did  not  appear  from  these  same 
depths  where  the  soil  was  made  compact  by  tamping. 

The  egg. — A few  eggs  have  been  taken  on  the  hop  roots  about  4 inches 
below  the  surface.  Obviously,  these  are  most  difficult  to  find  and  can  not  be 
detected  at  all  without  a magnifier.  To  more  easily  obtain  the  eggs  and  younger 
stages,  tin  cylinders,  8 inches  in  diameter  and  2 feet  high,  have  been  sunk  to  a 

depth  of  8 inches  in  the 
ground,  some  enclosing  hop 
vines  and  others  in  the 
open  field.  Large  numbers 
of  beetles  have  been  liber- 
ated in  each  of  these,  and 
they  will  be  taken  up  with 
the  soil  intact  in  the  tins  in 
two,  three,  and  four  weeks, 
and  the  soil  carefully  ex- 
amined for  eggs  and  larvae. 
Beetles  taken  in  mating, 
and  enclosed  in  vials  with 
earth  at  the  bottom,  have 
laid  eggs  in  from  eight  to 
ten  days. 

The  larva. — Larvae  of  what 
the  writer  believes  to  be 
this  flea-beetle  have  been 
taken  from  2 to  4 inches 
below  the  surface,  both 
around  hop  roots  and  in  the 
spaces  between  the  vines 
away  from  any  hop  roots. 
While  most  of  the  larvae 
have  been  taken  about  hop 
vines,  I think  that  they  are 
not  restricted,  in  feeding, 
to  the  roots  of  the  hop  ex- 
clusively, since  some  have 
been  taken  in  spaces  be- 
tween the  hop  vines  and 
also  because  of  the  wide 


Fig.  17. — Breeding  and  control  cage  in  place  over  a hill. 
(Original.) 


distribution  of  the  beetle,  both  in  the  United  States  and  in  the  valleys  of  the 
Chilliwack  and  Agassiz,  away  from  any  hopyards.  Search  about  the  roots  of 
the  nettle  and  other  plants  growing  along  the  borders  and  roadsides  failed  to 


reveal  any  larvae. 

The  pupa. — We  have  also  taken  pupae  of  what  was  considered  this  flea-beetle. 
Transformation  to  the  adult  was,  of  course,  necessary  to  establish  this  positively 
and  some  of  the  pupae  taken  to  the  laboratory  duly  transformed.  These  were 
taken  about  the  hop  roots  3 or  4 inches  below  the  surface. 

Both  larvae  and  pupae,  when  sought  at  the  same  time,  were  extremely  scarce, 
and  sometimes  an  hour’s  search  would  result  in  finding  nothing.  Earlier  in  the 


66 — vi 


THE  HOP  FLEA-BEETLE. 


81 


year  would  undoubtedly  be  a more  opportune  time  for  getting  the  younger 
stages,  but  our  rearing-cage  experiments,  starting  with  the  beetles  in  mating, 
should  give  us  ample  material  for  the  study  of  the  younger  stages.  The  scarcity 
of  the  larvae  at  the  time  when  sought  is  attributed  by  the  writer  to  the  fact 
that  it  was  too  late  for  the  large  numbers  of  spring  and  too  early  for  those 
expected  to  appear  about  six  weeks  later,  according  to  reports  of  previous  years. 
Those  few  which  were  obtained  are  probably  late  individuals  of  the  last  brood. 

Two  other  kinds  of  larvae  are  taken  commonly  in  the  ground,  these  being  wire- 
worms  and  carabid  larvae.  Many  of  these  are  very  small,  just  about  the  size  of 
our  flea-beetle  larvae,  and  the  wireworms,  when  first  hatched,  are  of  the  same 
white  color,  but  both  of  these  forms  of  larvae  can  be  readily  distinguished  from 
the  flea-beetle  larvae.  The  few  pupae  obtained  are  undoubtedly  those  of  what 
we  consider  the  flea-beetle. 

Development. — From  all  accounts  this  flea-beetle  keeps  emerging  continuously 
throughout  the  season,  though  there  are  periods  when  the  beetles  occur  much 
more  abundantly  than  at  others.  Last  year  Mr.  Hulbert  stopped  using  the 
tarred  boards  June  1,  when  practically  all  of  the  beetles  had  disappeared.  They 
did  not  reappear  until  the  last  week  in  July,  when  the  jarring  method  was 
resumed.  This  year  (1908)  he  continued  the  use  of  the  tarred  boards  up  to 
the  second  week  of  July,  this  difference  over  1907  being  attributed  to  the  cold 
wet  season.  According  to  this,  the  next  lot  of  beetles  may  not  appear  before 
the  last  of  August  of  the  present  year.  Beetles  have  been  seen  breeding  con- 
tinuously during  the  past  two  weeks,  though  not  abundantly,  one  pair  being 
seen  out  of  seventy-five  or  one  hundred  beetles.  Beetles  are  usually  present  in 
considerable  numbers  in  the  fall,  when  the  hops  are  mature,  and  do  much  direct 
injury  to  the  product. 


NOTES  ON  OTHER  SPECIES. 

A few  remarks  in  regard  to  the  larval  habits  of  our  other  American 
and  some  European  species  of  Psylliodes  may  be  interesting.  The 
writer  has  several  times  observed  the  beetles  of  the  equally  well- 
known  Psylliodes  convexior  Lee.  in  numbers  on  shepherd’s  purse 
(Bursa  bursa-pastoris)  in  June  near  the  District  of  Columbia,  and 
it  is  probable  that  this  is  the  larval  food  plant.  Until  the  publica- 
tion of  Mr.  Quayle’s  article  12  there  was  no  record  of  any  of  our  four 
species  having  been  reared;  hence,  the  natural  conclusion  that  they 
were  root-feeders.  In  Europe  no  less  than  forty-nine  species  of 
Psylliodes  are  recognized  in  a recently  published  catalogue,®  and  the 
habits  of  those  which  have  been  studied  indicate  a preference  for 
cruciferous  plants,  although  several  are  attached  to  widely  differ- 
ent groups  of  plants.  Thus  among  European  species  are  the  hop 
flea-beetle  ( Ps . attenuata  Koch),  the  potato  flea-beetle  ( Ps . affinis 
Payk.),  and  a species  which  is  mentioned  and  figured  by  Taschen- 
berg* 6  as  the  “ raps-erdfloh  ” (Ps.  chrysocephala  L.).  The  last  is 
very  abundant  and  has  been  known  for  years  to  attack  edible  crucif- 
erous crops.  It  has  been  recently  treated  (1900)  by  Mr.  Geo. 

® Reitter,  Catalogus  Coleopterorum  Enropse,  pp.  572-574,  1906. 

6 Praktische  Insekteii-Kunde,  Pt.  II,  p.  803,  fig.  79.  Bremen,  1879. 


82 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


H.  Carpenter  as  a cabbage  pest  in  an  article  in  which  the  larva  is 
described  and  illustrated  in  detail.  As  to  its  biology  Mr.  Carpenter  ° 
reaches  the  conclusion  that  the  female  beetle  lays  her  eggs  on  the 
underground  part  of  the  stem  and  that  the  young  larva  burrows 
through  into  the  interior  and  feeds  in  the  central  tissue  of  the  stem 
and  taproot  until  mature.  The  papal  stage  lasts  about  three  weeks 
and  is  passed  in  an  earthen  cell  just  beneath  the  surface.  The 
natural  larval  food  plant  is  evidently  a wild  crucifer. 

LOCAL  CONDITIONS  AND  NATURAL  INFLUENCES. 

Inquiry  was  made  of  Mr.  Eder  during  his  visit  to  Washington, 
D.  C.,  in  December,  1908,  as  to  the  local  conditions  in  the  infested 
area.  From  what  was  learned  through  him  it  would  appear  that  the 
insect’s  occurrence  in  such  great  numbers  in  the  hopyards  of  British 
Columbia  was  due  to  the  equable  temperature  and  to  the  humidity, 
which  keeps  the  soil  practically  always  sufficiently  moist  for  the  oper- 
ations of  the  larva?  feeding  beneath  the  surface. 

There  can  be  no  doubt,  from  the  writer’s  observations  of  our  east- 
ern flea-beetles,  that  these  are  largely  held  in  check,  especially  in 
regions  like  the  District  of  Columbia,  by  the  extremely  dry  heat  of 
midsummer.  At  the  time  that  the  flea-beetles  are  developing  as 
larvae  or  undergoing  their  transformation  the  ground  is  nearly  baked 
by  the  heat  during  the  day  and  softened  only  by  dews  at  night.  The 
conditions  are  very  different  in  British  Columbia,  and  there  are, 
moreover,  no  other  natural  causes  known  which  might  assist  in  de- 
pleting the  numbers  of  the  little  pest. 

Among  natural  agencies  only  a single  species  of  insect  has  as  yet 
been  discovered  preying  upon  this  flea-beetle,  a hymenopterous  para- 
site which  was  known  to  Fitch  2 and  which  he  mentions  as  a “ Chal- 
cidian.”  It  is  evidently  a species  of  Perilitus,  probably  the  same 
species,  schwarzii  Ashm.  ( ? ) , as  has  been  encountered  by  the  writer 
on  other  species  of  flea-beetles  of  the  genera  Epitrix  and  Phyllotreta. 
It  develops  within  the  body  of  the  adult  or  beetle.  It  is  not  known 
if  this  species  occurs  also  in  the  Pacific  region.  If  not,  it  might  be 
possible  to  introduce  it. 

Fitch’s  observations  and  conclusions  are  interesting,  since  we  have 
no  reason  to  doubt  his  theory.  Briefly  he  observed  on  June  4,  1863, 
two  flea-beetles  pairing  on  a leaf  of  rhubarb.  Presently  a parasite 
alighted  near  them.  It  darted  upon  the  back  of  the  female,  appear- 
ing to  be  inserting  its  sting  in  the  tip  of  her  body,  whereupon  she 
gave  a leap  and  they  both  disappeared  among  the  foliage.  Fitch 
conjectured  that  the  “ chalcidian  ” was  an  egg-parasite  of  the  flea- 

° Journal  of  Economic  Iliology,  Vol.  I,  pp.  152-150,  PI.  XI.  London,  England, 
November,  1900. 

GG— vi 


THE  HOP  FLEA-BEETLE. 


83 


beetle  and  that  the  eggs  of  the  latter  were  so  minute  that  the  larval 
parasite  required  several  of  them  to  nourish  and  bring  it  to  maturity, 
as  observed  of  an  egg-parasite  of  the  Hessian  fly.  The  parent,  watch- 
ing her  opportunity,  deposits  an  egg  internally  in  the  ovaries  of  the 
flea-beetle,  or  in  the  passage-way  therefrom,  and  the  parasite  larva, 
taking  up  its  residence  there,  consumes  the  eggs  of  the  flea-beetle, 
one  after  another,  as  they  develop,  whereby  none  of  them  will  be 
extruded  until  after  the  parasite  has  attained  its  growth.  In  con- 
clusion he  writes,  “ Most  singular  and  truly  wonderful  as  such  a 
provision  of  nature  would  be,  it  is  the  most  probable  conclusion  I am 
able  to  arrive  at  from  past  observations.” 

METHODS  OF  CONTROL. 

Correspondents  who  have  inquired  for  a direct  remedy  for  use  against 
this  species  have  been  advised  to  experiment  with  all  of  the  usual 
flea-beetle  remedies.  These  are,  in  brief,  arsenate  of  lead,  arsenate  of 
lead  with  resin-fishoil  soap,  Paris  green  with  and  without  Bordeaux 
mixture,  Sclieele’s  green,  arsenite  of  lime  with  soda,  dry  Paris  green 
with  air-slaked  lime,  Bordeaux  mixture  alone,  and  kerosene  emulsion. 
According  to  Messrs.  Eder,  Quayle,  and  others,  most  of  these  remedies 
have  been  tested  more  or  less  completely  without  being  found  to  be 
thoroughly  effective,  owing  to  the  great  numbers  of  the  flea-beetles  and 
the  rapidity  with  which  the  tops  of  the  hop  vines  grow.  All  remedies 
that  have  been  employed  have  been  directed  against  the  beetles  only. 
Unless  the  hop  plants  are  sprayed  nearly  every  day  it  is  practically 
impossible  to  keep  them  covered  with  any  poison  so  as  to  entirely  pro- 
tect them  from  the  ravages  of  the  “ fleas.”  Among  other  substances 
tested  were  tarred  boards  and  sheets,  as  for  leafhoppers.  On  account 
of  the  employment  of  cheap  labor,  chiefly  Hindu,  mechanical  and 
hand  methods  were  found  of  some  value.  Snuff  was  found  effective 
on  a small  scale  and  finely  powdered  tobacco,  such  as  is  now  on  the 
market  as  an  insecticide,  is  to  be  tested. 

According  to  Messrs.  Quayle,  Eder,  and  others,  the  difficulties 
encountered  in  the  economic  treatment  of  this  species  are  due  to  twTo 
causes:  (1)  The  continual  emergence  or  appearance  of  the  beetles, 
rendering  any  method  that  has  yet  been  employed,  such  as  an  arsen- 
ical or  contact  spray,  or  any  mechanical  means  of  capture,  such  as  jar- 
ring, of  only  temporary  value,  and  (2)  the  extremely  rapid  growth 
of  the  young  hop  vines,  making  frequently  repeated  applications  of  a 
spray  or  other  direct  remedy  a necessity. 


ARSENIC  ALS. 


Arsenate  of  lead. — Arsenate  of  lead,  applied  at  the  rate  of  about  1 
pound  in  from  20  to  50  gallons  of  water,  is  advised  for  use  against 

66 — vi 


34 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


the  hop  flea-beetle.  Being  more  adhesive,  this  mixture,  when  sprayed 
upon  the  plants,  sticks  more  firmly  to  the  leafage  than  Paris  green, 
and  is  also  very  much  less  likely  to  produce  scorching  or  burning; 
indeed,  it  has  been  used  at  1 pound  to  10  gallons  of  water  on  some  of 
the  hardier  plants,  such  as  potato,  without  injurious  effects.  This  is, 
however,  not  advisable,  owing  to  the  extra  cost,  provided  that  a 
weaker  solution  will  accomplish  the  object.  Moreover,  scorching  is 
apt  to  follow  its  use  at  this  rate  on  some  plants,  especially  when  these 
are  exposed  to  the  direct  rays  of  the  sun.  The  adhesiveness  is  still 
further  enhanced  by  the  addition  of  about  the  same  amount  by 
weight  of  resin-fishoil  soap  as  of  the  arsenical  employed.  Mr.  Wil- 
son reported  that  arsenate  of  lead,  applied  at  the  rate  of  4 pounds  to 
40  pounds  of  Bordeaux  mixture,  was  inadequate,  yet  Mr.  Quayle  re- 
ports that  used  at  the  rate  of  5 pounds  to  50  gallons  it  will  kill  a 
large  number  of  the  beetles,  although  many  take  to  the  new  growth 
that  is  constantly  appearing,  or  apparently  carefully  avoid  those 
places  on  the  foliage  that  have  a good  coating  of  poison.  The  failure 
of  these  two  arsenicals  must  be  attributed,  in  large  part,  to  unsuitable 
spraying  apparatus;  either  of  these  applications  should  kill  insects 
on  hops,  as  they  have  both  been  found  effective,  according  to  Fletcher, 
against  this  same  beetle  on  rhubarb  in  the  ‘Northwest  Territory  and 
Manitoba. 

Dry  Paris  green. — Mr.  Thos.  Cunningham  reported  that  very 
little  impression  was  made  by  an  arsenical  spray  in  the  region  just 
mentioned,  but  stated  that  Paris  green  dusted  on  the  plants  seemed  to 
produce  better  results.  It  was  applied  by  means  of  a Leggett  powder 
gun.  Even  then  some  trouble  was  experienced;  in  fact,  as  the 
arsenical  dust  or  so-called  “ dust  spray  ” struck  the  vines  the  “ fleas  ” 
hopped  to  the  ground.  “ In  all  my  experience  with  insecticides,”  he 
says,  “ I have  never  seen  anything  which  will  approach  the  fleas  in 
resistant  power.” 

Paris  green  spray. — Paris  green,  being  the  most  readily  obtainable 
insecticide,  was  advised  by  this  Bureau  when  information  as  to 
remedies  was  requested.  When  properly  prepared  and  applied, 
according  to  the  directions  furnished  in  Farmers’  Bulletin  No.  127, 
this  insecticide  should  have  no  deleterious  effect  on  the  hop  or  other 
plants  affected.  It  was  advised  that  other  food  plants  growing  in  the 
vicinity,  such  as  rhubarb,  turnips,  and  weeds,  should  be  sprayed  with 
the  solution. 

Regarding  its  efficiency  in  hop  fields  Mr.  John  Wilson,  in  a report 
to  the  late  Doctor  Fletcher,  stated  that  when  applied  at  the  rate 
of  from  4 to  8 ounces,  in  combination  with  Bordeaux  mixture,  made 
according  to  the  4-4  40  formula,  or  in  40  gallons  of  water,  it  was  not 

successful. 

66 — VI 


Spraying  Apparatus  Used  in  Hopyards  in  British  Columbia.  (Original.) 


Bui,  66,  Pt.  VI,  Bureau  of  Entomology,  U.  S.  Dept,  of  Agriculture. 


Plate  V. 


THE  HOP  FLEA-BEETLE. 


85 


For  use  against  this  species  in  its  occurrence  on  field  and  garden 
crops  in  Washington  State,  Messrs.  Piper  and  Doane  have  advised 
Paris  green.  The  former  states  that  he  obtained  excellent  results  by 
using  Paris  green  liberally  but  that  it  is  necessary  in  the  treatment  of 
young  plants  to  apply  the  remedy  as  soon  as  attack  by  the  beetles  is 
noticed.  Both  the  wet  and  the  dry  methods  are  advised,  as  well  as 
the  addition  of  Bordeaux  mixture. 

Other  arsenicals. — Other  arsenicals  advised  in  such  cases  are  arsen- 
ite  of  lime  with  soda,a  which  has  the  merit  of  being  as  effective  as 
Paris  green  and  lime  and  far  cheaper,  and  Scheele’s  green,  which  is 
similar  to  Paris  green  and  is  employed  in  the  same  manner.* 6 

SUMMARY  ON  THE  USE  OF  ARSENICALS. 

To  sum  up  the  directions  for  the  use  of  arsenicals,  it  should  be 
stated  that  arsenate  of  lead  should  take  first  place  because  it  can 
be  purchased  already  combined  in  paste  form,  and  especially  because 
it  contains  a smaller  percentage  of  free  arsenic  (60  to  TO  per  cent), 
and  is  therefore  less  likely  to  produce  scorching  or  burning;  and, 
moreover,  being  adhesive,  it  remains  on  the  plant  longer. 

Paris  green,  when  combined  with  lime  and  water,  or  with  Bor- 
deaux mixture,  is  almost  equally  as  good  as  arsenate  of  lead,  and 
is  more  readily  obtainable  in  most  markets,  the  ingredients  being 
purchasable  practically  anywhere.  It  is  quicker  in  action,  but  not 
so  adhesive. 

The  number  of  sprayings  will  naturally  depend  upon  the  locality 
and  seasonal  conditions ; possibly  it  may  be  necessary  to  spray  every 
few  days  when  the  plants  are  quite  young  and  the  beetles  are  most 
abundant.  Later  there  should  be  longer  intervals  between  sprayings. 

Dry  mixtures  are  as  a rule  not  in  the  same  class  with  the  sprays, 
as  they  can  not  be  applied  so  economically,  do  not  so  thoroughly 
cover  or  adhere  so  closely  to  the  leafage,  and  are  more  apt  to  cause 
burning  to  delicate  foliage.  Dry  Paris  green  mixed  with  air-slaked 
lime  in  the  proportion  of  about  1 part  of  Paris  green  to  10  or  20 
of  lime  is  sometimes  used,  but  is  less  effective,  and  frequently  much 
of  the  material  is  wasted  in  applying  it. 

The  spraying  apparatus  used  in  the  hopyards  of  British  Columbia 
is  shown  in  Plate  Y and  figure  18,  the  second  illustration  showing  a 
crew  spraying  hops  through  the  rows. 

CONTACT  SPRAYS. 

Among  the  contact  sprays  tried  during  1908  were  whale-oil  soap, 
1 pound  of  soap  to  10  gallons  of  water;  kerosene  emulsion,  J pound 

° Prepared  in  accordance  with  instructions  in  Farmers’  Bulletin  No.  283,  p.  37. 

6 Discussed  in  the  publication  quoted,  as  also  in  Farmers’  Bulletin  No.  127. 

66 — vi 


86 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


soap  and  1 gallon  of  kerosene  to  25  gallons  of  water;  resin,  1 pound 
to  16  gallons  of  water;  and  black  leaf  tobacco  extract,  1 gallon  to  65 
gallons  of  water.  Of  these  Mr.  Quayle  says  that  the  last  seemed  most 
effective,  with  kerosene  emulsion  next,  and  that  none  of  these  sprays 
in  the  given  proportion  injured  the  foliage  at  all. 

It  is  entirely  possible  to  kill  most  of  the  beetles  well  bit  by  the  spray,  but 
many  escape  between  clods  in  the  soil  or  are  protected  by  the  vine  or  are  con- 
cealed in  the  growing  tip.  The  percentage  killed,  however,  will  be  satisfactory, 
blit  this  [treatment]  must  be  repeated  so  often  that  the  operation  becomes 
laborious  and  costly. 

While  kerosene  emulsion  and  whale-oil  soap  are  practically  never 
advised  as  standard  remedies  for  mandibulate  or  chewing  insects, 


Fig.  18. — A crew  spraying  hops  in  British  Columbia.  (Original.) 

such  as  this  flea-beetle,  both  are  emplo}'ed  in  the  infested  terri- 
tory against  the  hop  aphis,  or  “louse,”  and  therefore  the  hop  grower 
is  familiar  with  their  preparation  and  use.  It  has  been  ascertained 
that  when  these  are  used  against  the  hop  aphis  the  flea-beetles  coming 
into  contact  with  the  emulsion  are  killed.  The  probabilities  are  that 
kerosene  emulsion  properly  prepared  and  applied  in  the  affected 
regions  will  be  considerably  less  expensive  than  a tobacco  extract,  and 
it  is  possible  to  make  a tobacco  extract  which  would  be  comparatively 
cheap.  In  recent  experiments  made  under  the  writer’s  direction  at 
Norfolk,  Va.,  whale-oil  soap,  used  at  the  rate  of  about  1 pound  to  10 
gallons  of  water,  employed  against  aphides,  has  proved  quite  as  ef- 
fective and  as  economical  as  kerosene  emulsion,  considering  the  fact 
go — vi 


THE  HOP  FLEA-BEETLE. 


87 


that  unskilled  laborers  are  likely  to  make  imperfect  emulsions  and 
waste  the  material  in  applying  it.  With  competent  help,  and  other 
things  being  equal,  kerosene-soap  emulsion  should  be  the  more  eco- 
nomical spray.  It  would  be  well  to  continue  the  use  of  kerosene  emul- 
sion at  varying  rates,  including  the  rate  that  has  been  already  used 
and  up  to  1 pound  of  soap  and  1 gallon  of  kerosene  emulsion  to  30 
gallons  of  water.  It  is  possible  that  if  the  emulsion  were  diluted 
with  10  gallons  of  water  still  better  results  might  be  obtained,  but  if 
labor  is  cheap  the  weaker  solution,  other  things  being  equal,  should 
prove  to  be  the  more  economical  preparation. 

BORDEAUX  MIXTURE. 

Bordeaux  mixture,  as  has  been  known  for  years  and  frequently 
demonstrated,  is  a powerful  deterrent  against  flea-beetles  and  other 
leaf-beetles,  and  its  use  should  be  continued.  Since,  as  appears  to  be 
demonstrated  by  the  observations  of  Mr.  Quayle,  this  flea-beetle  is 
quite  discriminating  in  taste,  it  would  be  well  to  apply  Bordeaux 
mixture  over  a considerable  surface  and  use  Paris  green  or  arsenate 
of  lead  for  the  remainder  of  a field,  i.  e.,  to  spray  the  majority  of  the 
plants  in  such  manner  that  those  which  reject  the  Bordeaux  mixture 
on  treated  plants  would  resort  to  those  sprayed  with  Paris  green  or 
arsenate  of  lead.  It  should  be  determined  which  of  these  two  insecti- 
cides has  the  greater  deterrent  effect  against  flea-beetles. 

MECHANICAL  AND  CULTURAL  METHODS. 

Trap  crops. — The  great  fondness  displayed  by  this  species  for 
rhubarb  suggests  the  use  of  the  latter  between  rows,  e.  g.,  in  th’e  vicin- 
ity of  woods,  as  an  attraction  or  lure  for  the  beetles,  it  being  believed 
that  the  beetles  will  concentrate  on  these  plants  and  thus  give  the  crops 
an  opportunity  to  grow  to  a sufficient  height  and  strength  to  be  able  to 
resist  the  ravages  of  the  pest.  Since  certain  cruciferous  crops  are 
also  attacked,  such  as  turnips,  it  is  further  suggested  that,  these  and 
other  varieties  like  swedes  and  rutabagas,  rape,  and  mustard  be 
employed.  In  the  mild  climate  of  the  infested  region  all  of  these 
can  be  grown  during  the  winter,  and  it  seems  probable  that  kale  will 
be  found  equally  effective.  Beets,  especially  mangels,  are  grown  in 
the  affected  region  and  tests  should  be  made  with  these  as  trap  crops, 
as  also  with  sugar  beet  in  regions  where  this  crop  can  be  grown 
profitably. 

Rolling  the  fields. — One  of  the  remedies  attempted  against  this  flea- 
beetle  in  its  occurrence  in  beet  fields,  as  reported  by  Doctor  Ball, 
consists  in  the  use  of  rollers.  He  reports  that  “ running  a corrugated 
roller  over  the  field  as  soon  as  the  damage  is  first  discovered  seems 

66 — VI 


88 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


to  have  a very  good  effect.  Just  why,  is  not  so  clear,  possibly  because 
it  loosens  the  ground,  breaking  up  any  crust  that  may  have  formed, 
and  allows  all  the  beets  to  get  through  at  one  time  and  in  this  way 
some  of  them  get  ahead  of  the  beetles.  The  farmers  think  it  kills 
the  beetles.  Cleaning  up  hedge-banks  and  rubbish  around  the  fields 
has  been  recommended  and  appears  to  have  had  a good  effect.  It  is 
a lamentable  fact  that  a field  that  is  slightly  weedy  when  the  beets 
appear  will  not  be  injured  as  badly  as  one  that  is  free  from  weeds, 
which  probably  accounts  for  the  fact  that  replanted  beets  are  rarely 
destroyed.” 

The  use  of  fertilizers. — Where  fertilizers  are  used  the  plants  are 
undoubtedly  aided  in  recovering  from  attack  by  this  flea-beatle,  but 
fertilizers  are  not  remedies.  Possibly  where  mineral  fertilizers  are 
applied  heavily  they  might  have  some  effect  on  the  larvae,  but  it  is 
doubtful  if  a sufficient  amount  of  an  irritant  salt  would  remain  in 
the  earth  to  destroy  any  large  percentage  of  larvae  at  the  time  when 
those  which  have  just  developed  from  the  egg  or  have  just  molted  are 
feeding  on  the  roots.  It  is  worth  mentioning,  however,  that  Mr. 
Theo.  Eder  noticed  that  when  a fertilizer  consisting  of  3 per  cent 
nitrogen  from  nitrate  of  soda,  12  per  cent  potassium  oxid  (K20) 
from  muriate  (chlorid)  of  potash,  and  9 per  cent  phosphorus  pen- 
toxid  (P205)  from  superphosphates  was  applied  there  were  prac- 
tically no  flea-beetles.  This  fertilizer,  however,  was  considered  too 
expensive,  owing  to  the  cheapness  of  hops  in  the  affected  region  of 
British  Columbia. 

Irrigation. — Irrigation  has  been  suggested  and,  on  the  authority 
of  Prof.  E.  G.  Titus,  the  flea-beetle,  when  it  is  working  on  sugar 
beets,  can  be  driven  away  during  irrigation  by  disturbing  the  beets, 
thus  causing  the  beetles  to  jump  into  the  water  and  be  swept  away.® 

Tarred  catchers. — Tarred  sheets,  boards,  or  similar  contrivances  on 
the  plan  of  “ hopperettes,”  in  use  against  leafhoppers,  have  been  em- 
ployed in  the  infested  region  for  capturing  the  flea-beetles.  Mr. 
Hulbert  reports  having  destroyed  large  numbers  by  catching  them 
on  tarred  sheets  as  they  fell  from  the  vines  after  being  disturbed. 
Mr.  Quayle  also  reports  success  with  a “ catcher  ” which  he  describes 
substantially  as  follows: 

The  receptacle  used  consists  of  a stout  canvas  about  3 feet  by  4,  to  which  is 
nailed,  on  the  under  side,  three  strips  of  boards  with  one  at  right  angles,  to 
keep  the  canvas  taut.  A handle  is  fastened  to  two  of  these  strips  to  project 
upward  and  backward,  by  means  of  which  the  apparatus  is  operated.  This  is 
lifted  from  vine  to  vine  and  the  beetles  jarred  off  with  wisps  of  hay.  Usually 
two  men  work  together  on  the  same  row,  the  two  canvases  placed  together  on 
each  side  of  the  vine. 

° Bui.  07,  Bur.  Ent.,  U.  S.  Dept.  Agr.,  p.  112,  1007. 

GG— vi 


Hop  Fields  from  which  Training  Twine  was  Removed  in  June  or  July,  Photographed  in  August. 

Beetles  abated  somewhat  the  last  of  July  and  hops  began  to  put  out  new  shoots.  Weed  growth  kept  down  by  sheep  pasturage.  Hop-leaf  growth  pastured  very 

close  in  fall.  (Original. ) 


Bui.  66,  Pt.  VI,  Bureau  of  Entomology,  U.  S.  Dept,  of  Agriculture. 


Plate  VI 


LIBRARY 

UNIVERSITY  Of  ILLINOIS 
URBftNA 


THE  HOP  FLEA-BEETLE. 


89 


This  method  captures  a satisfactory  percentage  of  the  beetles  and 
should  be  comparatively  inexpensive.  But  unfortunately  the  re- 
peated operations  which  are  necessary  bring  the  cost  to  a high  figure. 
It  cost  Mr.  Hulbert  last  year  approximately  $1.25  per  acre  for  each 
operation.  He  went  over  his  vines  six  times,  and  some  parts  of  the 
yard  eight  or  ten  times.  He  expected  to  go  over  it  at  least  twice 
more,  so  that  the  total  cost  would  be  from  $10  to  $15  per  acre. 

In  figure  19  a portion  of  a hop  field  is  shown  which  illustrates  the 
tarred  “ boards  ” in  place  for  use.  The  flea-beetles  are  dusted  off 
of  the  vines  upon  these  tarred  receptacles  with  wisps  of  hay,  as 


Fig.  19. — Portion  of  hop  field  with  tarred  boards  in  place.  Flea-beetles  are  dusted  with 
wisps  of  hay  from  the  vines  onto  tarred  boards.  (Original.) 


described  above.  All  of  the  vines  were  tanglefooted,  but  the  flea- 
beetles  went  up  the  poles  and  crossed  over  on  the  wires  overhead  until 
the  tanglefoot  was  applied.  Plate  YII  illustrates  the  method  of 
capturing  the  hop  flea-beetle  on  tarred  horse  sledges,  also  by  shaking 
the  vines.  Millions  were  captured  in  this  way. 

CLEAN  CULTIVATION. 

Frequent  stirring  of  the  soil  and  other  cultural  operations  seem, 
as  yet,  to  be  of  no  appreciable  help,  according  to  Mr.  Quayle,  and  the 
kind  of  soil  also  seems  to  have  little  or  nothing  to  do  with  the  abun- 

66— VI 


90 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


dance  of  the  beetles,  which  are  found  in  light,  sandy,  and  heavy  soils. 
Mr.  Quayle  further  says: 

The  control  measures  which  have  been  tried  have  been  necessarily  directed 
entirely  against  the  adult  or  beetle,  and  considering  the  rapid  growth  of  the 
vines  and  the  continuous  appearance  of  the  beetles  no  effective  and  practical 
remedy  has  yet  appeared.  With  further  work  on  the  younger  stages  it  may 
be  possible  to  find  here  a vulnerable  point  of  attack. 

One  of  the  most  promising  remedies  for  this  as  well  as  other  insect 
pests  is  the  employment  of  clean  methods  of  culture.  Since  it  has  been 
found  that  the  flea-beetles  ensconce  themselves  in  any  available  shel- 
ter, such  as  the  cracks  in  the  hop  poles,  even  although  these  may  have 
no  bark  remaining,  it  has  been  thought  desirable  to  dip  the  poles  in 
a preparation  which  will  not  only  close  the  cracks  but  which  will  also 
repel  the  pests.  Fuel  oil,  a grade  of  crude  petroleum,  is  being  tried, 
according  to  Mr.  Eder,  since  it  can  be  purchased  as  low  as  2 cents 
a gallon.  Tar  might  serve  the  same  purpose  and  should  act  as 
strongly  as  a repellent  and  close  the  cracks  more  closely  and  would 
not  be  so,  disagreeable  to  handle.  The  poles  are  dipped  into  the 
boiling  fuel  oil,  but  the  tar  would  also  have  to  be  heated  very  hot 
before  dipping. 

It  is  customary  to  plow  thoroughly  and  to  cultivate  where  possible 
so  as  to  keep  down  the  weeds,  and  this  method  of  tillage  must,  of 
course,  be  continued,  as  the  insects  find  food  in  weeds  of  the  kind 
which  have  been  mentioned  in  the  opening  paragraph,  viz,  dock, 
lamb’s-quarters,  pigweed,  and  the  like,  and  also  cruciferous  weeds. 
If,  by  preventing  the  insects  from  hibernating  in  the  hop  fields  in 
debris,  the  fields  can  be  practically  freed  from  them,  the  next  step 
is  to  prevent  their  hibernating  in  near-by  timber,  as  there  can  be 
little  doubt  that  in  such  places  are  their  favorite  winter  quarters. 
It  is  practicable  in  many  cases  to  cut  down  small  sections  of  timber 
in  order  to  accomplish  this  purpose. 

In  answer  to  the  question  as  to  the  remnants  after  the  hops  are 
picked,  Mr.  Eder  informed  the  writer  that  the  expedient  of  cutting 
the  tops  and  destroying  them  by  burning  led  to  the  discovery  that  the 
beetles  enter  into  the  hollow  stalks,  remaining  in  hibernation  there 
in  great  numbers.  With  the  discovery  of  this  habit  he  will  permit 
remnants  to  remain  as  long  as  there  is  any  prospect  of  the  insects’ 
trying  to  obtain  winter  shelter  in  them,  and  then  will  have  all  debris 
burned  at  about  the  time  of  the  first  frost.  One  method  of  destroy- 
ing field  remnants  and  weeds,  by  sheep  pasturage,  is  illustrated  by 
Plate  VI. 

The  writer  has  suggested  the  addition  of  burlap  wrapped  about 
the  poles  which  have  been  treated  with  tar  or  which  do  not  have  an 
odor  strong  enough  to  repel  the  insect.  This  will  attract  the  insects 
for.  hibernation,  and  can  be  removed  after  the  first  frost,  or  there- 

66 — VI 


Method  of  Capturing  Hop  Flea-beetles  on  Tarred  Horse  Sledges  by  Shaking  the  Vines-,  Millions  Captured  in  this  Way.  (Original.) 


Bui.  66,  Pt.  VI,  Bureau  of  Entomology,  U.  S.  Dept,  of  Agriculture. 


Plate  VII. 


library 

UNIVERSITY  OF  ILLINOIS 
URCANA 


THE  HOP  FLEA-BEETLE. 


91 


abouts,  and  thrown  into  hot  water,  and  after  drying  will  be  available 
for  use  in  other  seasons. 

If,  with  another  year’s  experience,  we  could  ascertain  how  best  to 
control  the  insect,  either  by  killing  the  beetles  with  arsenate  of  lead 
or  other  arsenical,  kerosene  emulsion,  or  whale-oil  soap,  or  by  destroy- 
ing the  larvae  in  the  ground,  the  problem  would  be  partially  solved. 
One,  two,  or  perhaps  even  three  of  these  remedies  might  be  used  in 
combination  and  excellent  results  obtained.  In  any  case,  if  we  can 
partially  control  the  insects  by  any  one  of  them  we  should  not  forget 
that  cultural  remedies,  and  especially  clean  culture,  are  the  most 
valuable  remedies  that  can  possibly  be  employed  against  insect  pests. 
Indeed,  wTith  many  species,  if  cultural  practices  were  properly  fol- 
lowed out,  with  the  cooperation  of  our  neighbors,  insecticides  would 
in  the  course  of  time,  after  the  balance  of  nature  had  been  restored, 
seldom  be  needed  save  in  case  of  severe  outbreaks,  which  are  likely 
to  occur  more  or  less  spasmodically  with  most  of  our  noxious  insects. 


LITERATURE. 


A complete  bibliography  of  this  species  is  appended  and  only  a 
brief  review  of  published  accounts  need  be  given.  The  original 
description  of  the  species  appeared  in  1847, 1 and  it  was  not  until 
twenty  years  later  that  we  had  any  record  of  the  insect’s  habits.  In 
1867  Fitch2  wrote  a two-page  account  regarding  injury  to  cucumber, 
rhubarb,  and  radish,  furnishing  notes  on  a parasitic  natural  enemy. 
In  1884  our  first  account  of  injury  to  hops,  a brief  one,  was  written 
by  Dr.  J.  B.  Smith.4  These  accounts  were  followed  by  one  from 
Piper0  on  injuries  to  certain  truck  crops  in  Washington  State  in  1895 
and  by  Doane  8 of  similar  injuries  in  1900.  The  writer7  noted  the 
abundance  of  the  species  on  rhubarb  near  Washington,  D.  C.,  in  1897. 
Forbes  and  Hart 9 have  given  a brief  account  of  the  insect  from  the 
standpoint  of  its  injuries  to  sugar  beet  in  Illinois,  and  Fletcher10’11 
published  two  accounts  of  the  species  in  1904  and  1907,  respectively. 
In  1908  was  published  II.  J.  Quayle’s  article,12  in  which  first  mention 
is  made  of  the  larval  habits  of  the  insect. 


BIBLIOGRAPHY. 


1.  Melsheimer,  F.  E. — Proc.  Acad.  Nat.  Sci.  Phila.,  Vol.  Ill,  p.  166,  1847. 

Original  description  from  Pennsylvania  as  Haltica  punctulata  n.  sp. 

2.  Fitch,  Asa. — 11th  Rept.  Ins.  New  York,  pp.  38-40,  1867. 

A 2-page  account  with  mention  of  food  plants  and  a parasite  ; observed  feeding  on 
cucumber,  rhubarb,  and  radish. 

3.  Fitch,  Asa. — Ill’d  Ann.  Reg.  Rural  Affairs,  1867-8-9,  Vol.  V,  p.  204,  1873. 

A brief  note,  with  mention  of  attack  on  cucumber  and  melon. 

4.  Smith,  J.  B. — Bui.  4,  o.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  p.  50,  1884. 

Mere  mention  of  occurrence  in  hopyards,  where  the  beetles  eat  small  holes  in  the 
leaves,  doing  no  great  damage. 

5.  Horn,  G.  H. — Trans.  Amer.  Ent.  Soc.,  Vol.  XVI,  pp.  310,  311,  319,  1889. 

Revised  technical  description,  distribution,  and  systematic  bibliography. 


92 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


6.  Piper,  C.  V. — Bill.  17,  Wash.  State  Agr.  Exp.  Sta.,  pp.  55,  56,  1895. 

Short  general  account,  with  list  of  food  plants.  Species  stated  to  be  “ by  far  the 
most  destructive  flea-beetle  in  the  State”  [of  Washington]. 

7.  Chittenden,  F.  H. — Bui.  9,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  p.  22,  1897. 

Short  note  on  abundant  occurrence  on  rhubarb  near  Washington,  D.  C. 

8.  Doane,  R.  W. — Bui.  42,  Wash.  Agr.  Exp.  Sta.,  pp.  11,  12,  figs.  2,  3,  1900. 

A 2-page  general  account  with  two  original  illustrations. 

9.  Forbes  and  Hart. — Bui.  60,  Univ.  111.  Agr.  Exp.  Sta.,  p.  472,  1900;  21st 

Rept.  State  Ent.  Ills.,  p.  124. 

A brief  account ; on  sugar  beet  in  Illinois. 

10.  Fletcher,  Jas. — Rept.  Entom.  and  Bot.  Canada  for  1903  (1904),  p.  177. 

Mere  mention  as  affecting  hops  at  Sardis,  B.  C.,  in  noticeable  numbers. 

11.  Fletcher,  Jas. — Rept.  Entom.  and  Bot.  Canada  for  1906  (1907),  p.  215. 

Account  of  injuries  in  the  Fraser  River  Valley,  B.  C.,  in  1906,  with  quotations 
from  John  Wilson,  Agassiz  ; Thos.  Cunningham,  Vancouver  ; and  H.  Hulbert,  Sardis, 
B.  C.,  which  include  experiences  with  remedies. 

12.  Quayle,  H.  J. — Journ.  Econ.  Ent.,  Vol.  I,  p.  325,  October,  1908. 

A short  article,  with  notes  of  injury  in  British  Columbia  ; account  of  habits,  all 
stages,  including  the  egg,  being  taken  3 to  6 inches  from  the  surface  of  the  ground, 
larvae  feeding  at  the  roots  of  hop  and  other  plants  growing  in  the  yards  ; list  of 
food  plants,  and  difficulties  of  applying  remedies. 

SUMMARY. 

The  hop  flea-beetle,  a minute,  black  insect,  feeds  on  various  succu- 
lent plants.  It  does  serious  damage  to  hops  in  British  Columbia  and 
less  injury  to  sugar  beet  and  vegetable  crops  in  the  Pacific  coast 
region. 

Its  life  history  is  only  partially  known,  but  all  stages  have  been 
found  about  the  roots  of  hops  and  the  larva  probably  feeds  on  most 
of  the  same  plants  as  the  adult.  It  is  feared  that  this  species  may 
become  an  important  hop-pest  in  Washington  and  Oregon,  and  it 
doubtless  does  more  injury  to  beets  than  is  generally  accredited  to  it. 
Injury  is  most  severe  to  young  plants,  but  on  sugar  beet  the  operations 
of  the  beetles  throughout  the  season  undoubtedly  have  a deleterious 
effect  and  necessarily  decrease  the  yield. 

The  abundance  of  the  beetles  when  they  appear  early  in  the  season 
on  young  plants,  their  constant  reappearance,  and  the  constant  new 
growth  of  the  plants  from  day  to  day  make  it  difficult  to  apply 
direct  remedies  with  more  than  temporary  benefit.  Where  the  hops 
are  sprayed  with  kerosene  emulsion  or  whale-oil  soap  for  the  hop 
aphis  the  numbers  of  the  beetles  are  lessened.  Among  measures 
which  give  promise  of  value  are  the  institution  of  clean  methods  of 
cultivation,  including  deep  fall  plowing,  treating  hop  poles  in  such 
manner  as  to  prevent  the  beetles  from  hibernating  in  them,  and  clear- 
ing all  remnants  from  fields  so  as  to  leave  them  as  bare  as  possible  to 
prevent  the  beetles  from  sheltering  there  in  winter.  Arsenate  of  lead, 
Paris  green,  kerosene  emulsion,  whale-oil  soap,  and  Bordeaux  mixture 
should  receive  further  tests,  as  should  the  employment  of  trap  crops 
in  the  manner  advised  in  this  article. 

66 — VI 


o 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY— BULLETIN  No.  66,  Part  VII. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


BY 


F.  H.  CHITTENDEN,  Sc.  D., 


In  Charge  of  Truck  Crop  and  Stored  Product  Insect  Investigations. 


Issued  July  19,  1909. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1909. 


CONTENTS. 


Page. 

Successful  use  of  arsenate  of  lead  against  the  asparagus  beetle 93 

A note  on  the  asparagus  miner 94 

Injurious  occurrence  of  the  pea  moth  in  the  United  States 95 

A new  western  root  maggot 95 

Notes  on  water-cress  insects 96 


ii 


U.  S.  D.  A.,  Bui.  66,  Part  VII. 


Issued  July  19,  1909. 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


MISCELLANEOUS  NOTES  ON  TRUCK-CROP  INSECTS. 

By  F.  H.  Chittenden,  Sc.  D., 

In  Charge  of  Truck  Crop  and  Stored  Product  Insect  Investigations. 

SUCCESSFUL  USE  OF  ARSENATE  OF  LEAD  AGAINST  THE 
ASPARAGUS  BEETLE. 

During  the  first  week  of  June,  1908,  Mr.  W.  A.  Orton  reported  the 
common  asparagus  beetle  ( Crioceris  asparagi  L.)  very  injurious  at 
Takoma  Park,  D.  C.,  and  made  some  experiments  with  arsenate  of 
lead  with  complete  success.  Directions  for  application,  as  given  in 
Circular  102  of  this  Bureau,  were  followed.  The  first  application  was 
made  with  1 pound  of  arsenate  of  lead  to  20  gallons  of  water  and  the 
second  a week  later,  as  the  plants  had  grown  rapidly  in  the  mean- 
time and  a great  many  new  larvae  had  hatched.  The  second  appli- 
cation was  made  at  the  rate  of  1 pound  to  15  gallons  of  water.  The 
first  application  destroyed  most  of  the  insects,  but  after  a few  days 
a considerable  number  had  developed.  These  appeared  to  have  been 
all  killed  the  day  after  the  second  spraying.  Neither  spraying  seemed 
to  injure  the  plants  in  the  least,  but  the  liquid  adhered  in  fine  drops  to 
the  foliage  and  was  visible  there  for  some  time.  An  unsprayecl  plat 
on  a neighbor’s  place  was  considerably  injured  by  these  insects,  and  up 
to  July  1 no  more  had  appeared  on  Mr.  Orton’s  crop.  He  pronounced 
the  treatment  very  effective.  The  work  was  done  with  a compressed-  , 
air  machine  or  autospray. 

Mr.  Edward  A.  Eames,  Buffalo,  N.  Y.,  writing  of  the  value  of 
arsenate  of  lead  as  a means  of  combating  the  common  asparagus 

Note. — The  accompanying  Part  VII  includes  short  notes'  on  some  of  the 
insects  which  have  been  treated  in  earlier  parts  of  this  bulletin  and  notes  on 
two  insects  not  hitherto  recorded  as  injurious  in  the  United  States.  To  the 
former  class  belong  notes  on  the  asparagus  beetles  and  the  asparagus  miner, 
species  considered  more  in  detail  in  Part  I,  pages  1-10,  and  notes  on  water- 
cress insects  in  addition  to  what  has  been  published  in  Part  II,  pages  11-20. 
To  the  second  class  belong  notes  on  the  injurious  occurrence  of  the  pea  moth  in 
the  United  States  and  a short  account  of  a new  western  root-maggot. — F.  H.  C. 

93 


94 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


beetle,  stated  that  the  larvse  of  this  species  threatened  to  devour  his 
this  year’s  spring-set  asparagus  to  the  ground.  But  after  one  thor- 
ough spraying  with  arsenate  of  lead  it  was  difficult  to  find  any  but 
dead  larvae  on  the  plants.  Successive  sprayings  were  of  course  neces- 
sary, because  the  beetles  continued  to  come  from  neighboring  gardens 
to  deposit  eggs  on  the  plants  and  because  the  developing  plants  con- 
tinually presented  fresh  unsprayed  foliage  for  larval  food. 

Mr.  Eames  stated  positively  that  arsenate  of  lead  adhered  well, 
even  through  several  rains,  just  as  its  various  promoters  claimed — 
a fact  which  justifies  its  use  in  any  case  even  at  more  initial  cost 
than  other  poisons  which  might  be  used.  He  also  expressed  the  view 
that  asparagus  growers  generally  should  be  impressed  with  the  fact 
that,  because  of  the  tendency  to  spray  only  once,  additional  informa- 
tion should  be  given  of  the  value  of  extra  applications.  In  conclusion, 
he  stated  that  he  believed  arsenate  of  lead  was  a specific  for  this 
class  of  insects. 

Our  correspondent  is  undoubtedly  right.  It  seems  to  be  as  nearly 
a specific  for  asparagus  beetles  as  anything  that  can  be  obtained, 
provided  it  is  applied  according  to  directions  and  that  applications 
are  repeated  as  often  as  necessary.  The  trouble  is  that  many  truck 
growers,  after  spraying  a single  time,  consider  that  the  matter  should 
then  be  dropped,  and  if  the  desired  result  is  not  produced,  i.  e.,  if  the 
trouble  is  not  wholly  stopped,  the  spraying  is  condemned  or  at  any 
rate  the  insecticide  is  discontinued,  while  all  that  is  necessary  for 
the  entire  season  is  a second  or  third  application. 

A NOTE  ON  THE  ASPARAGUS  MINER. 

The  asparagus  miner  ( Agromyza  simplex  Loew)  was  reported  by 
Mr.  I.  J.  Condit  in  the  vicinity  of  Antioch,  Cal.,  August  19,  1908, 
where  the  common  asparagus  beetle  was  also  abundant.  The  miner 
was  said  to  be  equally  numerous  and  stalks  showing  infestation  were 
received.  The  miner-infested  stalks  could  generally  be  detected  by 
their  roughened  appearance  near  the  ground. 

This  species  was  also  taken  by  Mr.  Condit  at  Oakley  and  it  seems 
probable,  since  the  common  asparagus  beetle  is  found  in  both  local- 
ities, that  it  is  becoming  generally  distributed  in  California.  In  one 
place  at  Oakley  Mr.  Condit  observed  the  miner  quite  common  on  some 
stalks,  but  it  did  not  appear  to  be  equally  common  over  the  entire 
ranch. 

During  October,  1908,  the  writer  observed  this  species  well  estab- 
lished on  asparagus  in  the  vicinity  of  Portsmouth,  Va.  In  October, 
also,  Mr.  J.  B.  Norton  reported  very  severe  injury  to  asparagus  in 
the  vicinity  of  Concord,  Mass.  The  roots  of  the  plants  were  not 
only  girdled,  but  the  miners  worked  up  the  stalks  some  inches  above 
the  ground. 


MISCELLANEOUS  NOTES  ON  TRUCK-CROP  INSECTS. 


95 


INJURIOUS  OCCURRENCE  OF  THE  PEA  MOTH  IN  THE  UNITED 

STATES. 

Prominent  among  the  injurious  occurrences  of  the  year  1908  was 
the  discovery  of  the  pea  moth  ( Enarmonia  nigricana  Steph.)  for  the 
first  time  in  the  State  of  Michigan.  August  10  we  received  from  Mr. 
J.  E.  W.  Tracy,  Bureau  of  Plant  Industry,  specimens  of  the  larva  of 
this  species  and  its  work  in  growing  peas  and  pods  from  Charlevoix, 
Mich. 

Mr.  Tracy  wrote  that  he  obtained  the  specimens  on  that  day  and 
some  days  earlier  and  that  Mr.  E.  W.  Coulter  and  others  in  that 
vicinity  knew  nothing  of  the  identity  of  this  insect^  which  was  causing 
them  considerable  concern.  The  caterpillar  first  showed  itself  in 
very  small  numbers  four  or  five  years  before,  but  it  had  increased 
rapidly  until  the  year  of  writing,  when  15  per  cent  of  the  peas  were 
ruined.  The  insect  appears  to  start  operations  by  eating  the  embryo 
stem  and  then  moves  along  the  pod  until  it  makes  its  exit  and  dis- 
appears. Early  varieties  of  peas  were  the  worst  sufferer  in  the 
affected  district.  At  the  time  of  writing  our  correspondent  found  a 
less  number  of  living  larvae  than  previously. 

This  appears  to  be  the  first  record  of  the  appearance  of  this  insect 
in  the  United  States,  although  it  has  been  known  as  a pest  in  Canada 
for  several  years  and  has  undoubtedly  been  present  in  our  Northern 
States,  where  peas  are  grown,  without  having  been  recognized  as 
anything  new  or  unusual. 

A two-page  account  of  this  species  has  been  published  by  the  writer 
in  Bulletin  No.  83,  pages  96-98,  which  includes  a brief  illustrated 
description  of  the  moth  and  larva  and  a consideration  of  the  distri- 
bution, nomenclature,  history,  habits,  and  remedies. 

This  insect  first  came  to  notice  near  Toronto,  Ontario,  in  1898,  and 
notices  of  its  ravages  in  Canada  were  given  in  several  subsequent 
years  by  the  late  Dr.  James  Fletcher  in  his  report  as  entomologist 
and  botanist  of  the  Dominion  of  Canada.  It  is  an  importation  from 
the  Old  World  and  is  well  established  in  New  Brunswick  and  Nova 
Scotia  as  well  as  in  Ontario,  and  is  also  recorded  from  Manitoba. 

The  name  of  this  species  was  omitted  from  the  Dyar  catalogue  of 
Lepidoptera,  but  is  included  in  Smith’s  Check  List  of  Lepidoptera 
under  No.  5702.  In  most  publications  the  species  is  mentioned  as 
Semasia  nigricana. 

A NEW  WESTERN  ROOT  MAGGOT. 

August  16, 1907,  Mr.  E.  M.  Ehrhorn  sent  from  San  Francisco,  Cal., 
some  radishes,  the  roots  of  which  were  affected  by  a maggot.  The 
adults  were  reared  September  3 to  20  and  were  referred  to  Mr.  D.  W. 
Coquillett  for  identification.  They  were  first  mistaken  for  Pegomya 
cepetorum , because  of  the  very  close  relation  of  the  two  species,  but 


96 


SOME  INSECTS  INJURIOUS  TO  TRUCK  CROPS. 


when  more  material  of  both  sexes  was  obtained  they  were  seen  to  j 
be  different.  Mr.  Coquillett  states  that  some  individuals  have  the  I 
bristles  practically  as  in  cepetorum , but  in  the  males  the  median 
black  stripe  of  the  abdomen  is  continuous.  This  material  corresponds  j 
so  well  with  Stein’s  description  a of  Chortophila  planipalpis  as  to 
leave  no  reasonable  doubt  of  the  species.  The  type  locality  is  Idaho. 
The  insect  will  therefore  be  known  as  Pegomya  planipalpis  Stein, 
and  may  be  called  the  western  radish  maggot.  Another  lot  of  the 
maggot  was  received  from  the  same  source  October  1,  larvae  and 
pupae  both  being  present.  From  this  lot  adults  issued  November 
1 to  21. 

November  21,  1908,  we  received  from  Mr.  Charles  Heise,  Aber- 
deen, Wash.,  a section  of  turnip  mined  by  larvae  which  are  probably 
of  this  species,  as  also  a number  of  puparia.  Our  correspondent 
stated  that  his  observations  showed  that  the  maggot  works  on  onions 
as  well  as  on  turnips.  As  we  do  not  know  to  the  contrary,  and  do 
not  know  positively  of  the  occurrence  of  any  onion  maggot  in  that 
State,  this  surmise  may  be  correct.  It  remains  to  be  verified  or  dis- 
proven.  The  seed-corn  maggot  ( Pegomya  fusciceps  Zett.)  occurs 
in  that  region  and  is  more  apt  to  be  the  onion-feeding  species. 

Two  natural  enemies  of  this  radish  maggot  have  come  under  ob- 
servation and  have  been  identified  by  Mr.  J.  C.  Crawford,  as  follows : 

Aphwreta  sp. — September  3,  1908,  many  braconids  of  a species  of 
the  genus  Aphcereta  emerged  from  material  in  which  this  root- 
maggot  was  breeding  in  infested  radish  from  San  Francisco,  Cal. 
It  is  a small  species,  shining  black  in  color,  with  dusky  wings  and 
^yellow  legs.  In  some  specimens  there  are  21  joints  to  the  antennse 
on  one  side  and  22  on  the  other.  It  is  very  similar  to  the  type  of 
muscce , but  is  larger. 

Polypeza  sp. — This  species  was  reared  from  its  host  October  10, 
1907,  and  appears  to  be  undescribed. 

NOTES  ON  WATER-CRESS  INSECTS. 

The  water-cress  leaf -beetle. — May  2,  1907,  Mr.  J.  W.  Bryan  brought 
to  this  office  from  Halltown,  W.  Va.,  specimens  of  the  water-cress 
leaf-beetle  (Phaedon  aeruginosa  Suffr.),  present  in  the  beetle  and 
larval  forms,  the-  larvae  at  that  time  about  half  grown.  The  beetles 
were  beginning  to  die  and  a fungus  attack  vTas  noticed  w7hen  received. 
Numerous  individuals  of  the  beetle  and  one  larva  wTere  parasitized  by 
the  fungus.  The  fungus  was  tentatively  determined  by  Mr.  Haven 
Metcalf,  Bureau  of  Plant  Industry,  as  Entomophthora  splmrosperma. 
If  this  identification  is  correct,  there  can  be  no  doubt  that  the  fungus 
attacked  the  insect  before  death,  and  may  therefore  be  a factor  of 
value  in  its  natural  destruction. 

a Berl.  Ent.  Zeitschr.,  Vol.  XLII,  pp.  234-235,  1897. 


MISCELLANEOUS  NOTES  ON  TRUCK-CROP  INSECTS. 


97 


Since  the  publication  of  the  writer’s  preliminary  articles  on  the 
water-cress  leaf -beetle  and  sowbug  in  the  present  bulletin  (pp.  11-20) 
it  has  been  noticed  that  earlier  accounts  of  the  related  European 
Phoedon  betulce  L .,  known  as  the  mustard  beetle  and  “blackjack,” 
were  made  by  Miss  E.  A.  Ormerod,  who  furnished  several  references 
with  illustrations  in  her  manual.®  From  this  account  it  appears  that 
injury  was  first  noticed,  at  least  in  England,  in  1854,  to  white  mustard 
crops  near  Ely.  Another  account  of  this  insect  is  given  in  the  same 
author’s  report  for  1886. & 

The  'water-cress  soicbug. — April  16, 1907,  Mr.  C.  A.  Killinger,  Ship- 
pensburg,  Pa.,  sent  specimens  of  the  water-cress  sowbug  ( Mancasellus 
brachyurus  Harg.)  in  different  stages,  stating  that  it  was  destroying 
his  water  cress,  working  on  the  leaves  under  water,  cutting  them  close 
to  the  stem.  If  the  cress  is  light  or  does  not  grow  fast,  as  happens  in 
winter,  they  also  work  on  the  stems  and  roots,  cutting  the  plants  loose 
and  causing  them  to  float  downstream.  Our  correspondent  thought 
that  this  species  was  brought  to  that  section  from  Virginia. 

Experiments  conducted  with  lime  in  a small  spring  the  previous 
summer  succeeded  in  killing  most  of  the  sowbugs,  but  plenty  of  them 
remained  at  the  time  of  writing.  The  lime,  however,  burned  the 
cress,  causing  it  to  turn  yellow. 

December  23,  1908,  Mr.  F.  W.  Houston,  a grower  and  shipper  of 
water  cress  at  Lexington,  Va.,  wrote  of  this  species,  inquiring  for 
literature  and  a remedy.  He  stated  that  he  had  a spring  under  culti- 
vation that  was  infested  with  the  wrater-cress  sowbug,  and  later — 
March  11,  1909 — he  sent  specimens.  In  this  connection  he  wrote  as 
follows : 

I have  a spring  under  cultivation  which  has  been  infested  by  them  for  several 
years.  I fought  them  for  a time  by  putting  the  water  into  ditches  and  exposing 
the  rest  of  the  cress  bed  to  the  sun.  In  these  ditches  I would  make  frequent 
applications  of  lime ; this,  of  course,  was  done  during  the  early  summer,  after 
the  shipping  season  closes.  It  seems  to  kill  all  of  the  sowbugs,  but  when  I put 
the  water  into  the  beds  and  reset  the  cress,  hauling  it  from  an  uninfested  spring, 
it  was  not  long  until  the  “ bugs  ” were  again  noticed,  and  in  a short  time  they 
were  as  thick  as  ever. 

Mr.  Houston  was  advised  that  in  the  case  of  the  old  beds  the  water 
should  be  drawn  or  turned  off  and  that  the  cress  should  be  completely 
destroyed  and  the  spring  reset  with  uninfested  cress. 

a Manual  of  Injurious  Insects  and  Methods  of  Prevention.  London,  1890, 
pp.  151-156. 

b Report  on  Injurious  Insects  for  1886,  pp.  59-60. 


o 


